[CANCER RESEARCH 44, 5409-5414, November 1984]

Potential Utility of Serum Neuron-specific Enolase Levels in Small CellCarcinoma of the Lung1

David H. Johnson,2 Paul J. Marangos, James T. Forbes, John D. Hainsworth, R. Van Welch, Kenneth R. Hände,

and F. Anthony Greco

Department of Medicine, Division of Oncology, Vanderbilt University Medical Center, Nashville, Tennessee 37232 [D. H. J., J. T. F., J. D. H., R. V. W., K. ft H., F. A. G.],and Unit of Neurochemistry, Biological Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland 20205 [P. J. M.j

ABSTRACT

To assess the value of neuron-specific enolase (NSE) as a

possible biomarker of small cell lung cancer, serum levels weredetermined by radioimmunoassay in 93 newly diagnosed untreated patients and were compared to the NSE levels of 20healthy adult controls [9.6 ±0.7 (S.E.) ng/ml]. Serum NSE waselevated (>20 ng/ml) in 73% of all patients including 23 of 39(59%) with limited-stage disease and 45 of 54 (83%) with extensive-stage disease. The mean serum NSE was significantlyhigher in extensive-stage disease (94.5 ±13.8 ng/ml) comparedto the mean value for limited-stage disease (33.7 ±4.7 ng/ml) (p

< 0.001). NSE was elevated in all patients with three or moresites of metastatic disease. Serial NSE determinations wereobtained on 57 small cell lung cancer patients. NSE levels fell in40 of 50 (80%) of patients responding to treatment, increased in5 of 7 (71%) of patients with progressive disease, and increasedin 30 of 35 (86%) of patients who relapsed. A persistent rise inserum NSE occurred as many as 12 weeks before the clinicalrecognition of relapse in 15 of 23 (65%) of patients for whomadequate serial NSE data were available. These findings indicatethat serum NSE may be a useful marker for staging, monitoringtreatment, and predicting relapse in patients with small cell lungcancer.

INTRODUCTION

During the past decade, the treatment of small cell carcinomaof the lung has improved considerably such that 50 to 80% ofpatients with limited-stage disease and 25 to 40% of extensive-

stage patients will achieve a complete remission during initialtherapy (10). Unfortunately, 75 to 80% of patients with limited-stage disease and nearly all of the patients with extensive-stage

disease eventually relapse and die with lung cancer (10, 19).Efforts to improve the dismal prognosis of these individuals havefocused not only on attempts to improve chemotherapy andradiation treatment but also on methods of improving or refiningcurrent staging techniques (14), monitoring treatment response(29), and predicting relapse (8, 29). A tumor marker whichaccurately reflected tumor burden and mirrored the clinical condition of individual-small cell lung cancer patients could potentially

aid in the management of this disease (29).Recently, large amounts of NSE3 have been detected by both

'Supported in part by NIH Grants 1-RO1CA27333 and R-25CA19429, American

Cancer Society Grant JFCF-714, and the Saint Thomas Hospital Research Fund.Presented in part at the 75th Annual Meeting of the American Association forCancer Research, May 1984, Toronto, Ontario, Canada.

'Recipient of an American Cancer Society Junior Faculty Clinical Fellowship. To

whom requests for reprints should be addressed.°Theabbreviations used are: NSE, neuron-specific enolase; NSCLC, non-small

cell lung cancer.Received February 22, 1984; accepted July 26, 1984.

immunoperoxidase staining and radioimmunoassay in a varietyof neuroendocrine tumors but in none of the non-neuroendocrine

neoplasms tested (27). In order to determine if NSE could serveas a biomarker of small cell lung cancer, we measured the serumNSE levels in 93 newly diagnosed untreated patients treated atour institution between January 1980 and January 1983. Theresults, reported herein, indicate that serum NSE is a usefulbiomarker to follow before and during treatment of small celllung cancer patients and may help predict the recurrence ofdisease before it is otherwise clinically detected.

MATERIALS AND METHODS

Ninety-three patients with histologically confirmed small cell lung can

cer were staged prior to chemotherapy with radionuclide liver and bonescans; radionuclide brain scan, or head computer-assisted tomography

scan, or both; fiberoptic bronchoscopy; and bilateral posterior iliac crestbone marrow aspirations and biopsies. Limited-stage disease was de

fined as tumor confined to the hemithorax and/or ipsilateral mediastinaland supraclavicular nodes. Patients with disease beyond these siteswere classified as extensive disease. All patients received combinationchemotherapy with a cyclophosphamide-, doxorubicin-, and vincristine-based regimen administered every 3 to 4 weeks along with whole-brain

and thoracic irradiation in selected cases as described previously (9,11,13, 30). Prior to each treatment, patients were evaluated with a physicalexamination, complete blood count, platelet count, and a chest X-ray.

Restaging was performed routinely after 6 cycles of chemotherapy andconsisted of a repetition of all initially abnormal studies. A completeremission was defined as total clinical and pathological resolution ofdisease; a partial remission required at least a 50% reduction in the sumof the product of the perpendicular diameters of all measurable lesionsor a 50% or greater reduction in all évaluablelesions. Anything less thana partial response was judged as no response. Following completion ofchemotherapy, patients were evaluated at 4- to 12-week intervals in theVanderbilt or Veterans' Hospital oncology clinics with a physical exami

nation, chest roentgenogram, complete blood count, and platelet count.Blood chemistries were obtained when clinically indicated. Any physicalor laboratory abnormality suggestive of recurrent disease was evaluatedwith appropriate confirmatory studies. An effort was made to documentall relapses pathologically; however, this was not always possible. In thelatter situation, a finding such as the onset of a new neurological findingassociated with a brain scan abnormality consistent with métastaseswas taken as clinical evidence of recurrent disease.

Blood was collected from each of the 93 patients at diagnosis,between 9 a.m. and 12 p.m. Serial samples were obtained from 57 ofthese patients (21 with limited-stage disease; 36 with extensive-stagedisease) also between 9 a.m. and 12 p.m., usually at 3- to 6-week

intervals during treatment up to the time of restaging but less frequentlythereafter. Samples were immediately placed on ice and centrifugedwithin 30 to 45 min, after which each sample was divided into multiplesmall aliquots to be stored at -70° until assayed.

NSE was prepared from human brain as described previously, andantisera were raised in New Zealand White rabbits (16). The antiserumwas highly specific as judged by its total lack of reactivity with nonneu-

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roñalenolase. Serum was assayed ¡ntriplicate (50:1 in 0.5 ml totalvolume) using a double-antibody radioimmunoassay as described previ

ously (20). Intraassay variance was <5% and interassay variance rangedbetween 5 and 7%.

Student's f test was used to determine the statistical significance

between the means.

RESULTS

The mean serum NSE level in 20 healthy adult controls was9.6 ±0.7 (S.E.) ng/ml, which is slightly higher than that reportedpreviously (1, 4). A serum NSE greater than 20.0 ng/ml wasconsidered elevated inasmuch as this level is 3 standard deviations above the mean. Overall, 73% (68 to 93) of our patientshad an elevated pretreatment serum NSE level. NSE was raisedin 23 of 39 (59%) limited-stage patients and 45 of 54 (83%) ofpatients with extensive-stage disease. The mean pretreatmentNSE in limited-stage disease was 33.7 ±4.7 ng/ml (range, 7.6to 143.6 ng/ml) versus 94.5 ±13.8 ng/ml (range, 11.9 to 506.5ng/ml) for extensive-stage disease (p < 0.001). NSE levels

tended to correlate with extent of disease; e.g., the mean NSElevel of patients with one site of metastasis is 36.8 ±4.9 ng/ml(11.2 to 91.2 ng/ml) that for 2 metastatic sites is 96.5 ±21.0

so

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NUMBER OF METASTATIC SITES

Chart 1. Correlation of mean (X) NSE levels in normal adult controls comparedwith the number of metastatic sites in patients with extensive-stage disease.

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SITES OF SOLITARY METASTASES

Chart 2. Mean (X) serum NSE levels In extensive-stage disease with solitarysites of metastasis according to location of metastasis. BM, bone marrow; CWS,central nervous system.

ng/ml (13.5 to 243.1 ng/ml) (p < 0.001), and that for 3 or moremetastatic sites is 186.4 ±46.2 ng/ml (84.6 to 506.5 ng/ml) (p= 0.05) (Chart 1). All patients with 3 or more sites of métastaseshad an elevated pretreatment NSE. However, it was not possibleto predict specific sites of metastatic disease based on individualNSE levels. Interestingly, patients with isolated central nervoussystem métastaseshad elevated pretreatment NSE in only 2 of6 cases with a mean value lower than that in individuals withother isolated sites of disease (Chart 2).

Sería!NSE levels were obtained in 21 patients with limitedstage disease, 14 (67%) of whom had an elevated pretreatmentvalue. Of these 21 patients, 20 (95%) achieved a partial orcomplete remission. Serum NSE declined in 13, remained essentially stable in 4, and increased in 3 (Chart 3). Two of the limited-stage-disease patients with increasing NSE levels at restaging

had values which nevertheless remained within the normal range.The single limited-stage-disease patient who failed to respond,

i.e., had progressive disease, had a significant increase in theNSE at the time restaging was performed from 7.6 ng/ml atdiagnosis to 33.3 ng/ml at restaging. Of the 10 limited-stage-

disease patients who achieved a complete remission, the meanNSE at restaging was 17.3 ±2.2 ng/ml (range, 5.1 to 24.8 ng/ml) versus 21.4 ±3.4 ng/ml (range, 7.0 to 39.6 ng/ml) for the 10patients achieving a partial response, a difference not significantly different (p > 0.1).

Relapse data are available for 12 limited-stage-disease pa

tients, 11 (92%) of whom had a significant elevation in serumNSE at the time recurrence was clinically recognized (usuallybecause of an obvious new metastasis or local relapse detectedby chest roentgenogram and confirmed by fiberoptic bronchos-

copic biopsy) (Chart 3). The sole patient whose NSE declined at

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Serum Enolase in Small Cell Lung Cancer

Chart 3. A, serial serum NSE levels in small cell lung cancer patients with limited-stage disease at diagnosis, restaging, and relapse; B, serum NSE levels at restagingin limited-stage-disease patients either who remain in remission or for whom serial values are not available. O, NSE levels that are discordant with clinical findings; Q,progressive disease.

Table 1

Serum WS£levels prior to clinical recognition of relapse

NSE before Interval priorNSE at restag- clinical relapse to clinical re-

Patient Response ing (ng/ml) (ng/ml) lapse (wk)

ISO

1234567a9101112131415PR'CRCRCRPRPRPRPRCRPRCRCRPRCRPRLimited-stagedisease33.023.320.119.017.5Extensive-stage

disease14.429.617.917.936.020.815.194.113.614.043.272.026.835.649.030.552.965.839.971.555.543.0140.642.527.7412884281284444124

I25

Z. IOO

53 50

25

sQlvogechemotherapy

relapse

16 20 24 28 32

WEEKS OF TREATMENT

40 44 48

PR, partial remission; CR, complete remission.

relapserecurredwith biopsy-provensmall cell lung cancerass.c. nodules.Five limited-stage-diseasepatientshad sufficientserialNSElevelsto evaluatethe patternof NSEchangepriortoclinicalrecognitionof relapse,all of whom had an elevationinNSEfrom4 to 12weeksbeforeclinicalrecognitionof recurrence(mean,7.2 weeks;Table 1). The courseof one such patientisillustratedin Chart4.

Thirty-twoof the 36 (89%)patientswith extensive-stagediseaseand serialmeasurementsof serumNSEhad an elevatedpretreatmentvalue.The overallresponserate of this group of

Chart 4. Serial NSE levels in a limited-disease patient. NSE level falls at restaging and then begins to rise 12 weeks prior to relapse. A second response is inducedwith salvage therapy with concomitant fall in serum NSE. CR, complete remission.

patientswas83%(30of 36)including10completeand20partialremissions.Of the respondingpatients,27 hadhadan elevatedpretreatmentNSE,26 (96%)of whichdeclinedtoward normalwith treatment(Chart5). Threepatientshad clinicalresponsesassociatedwith eithera progressiveincreaseor stableserumNSEat restaging.In eachof the lattercases,the pretreatmentNSE level had been normalor near normal.One respondingpatienthada pretreatmentNSElevelthat was at the upperlimitof normalbutwhichfurtherdeclinedat restaging.Fourof 6 (67%)patientswithprogressivediseasehadanincreaseinserumNSE,while2 (33%)hadminimalregression(Chart5).Nineof 10(90%)

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Charts. A, NSE determinations in small cell lung cancer patients with extensive-stage disease at diagnosis, restaging, and relapse. O, discordant NSE values. B,NSE levels in extensive-stage-disease patients with progressive disease (O) or at restaging (•)without serial determinations.

complete responders and 8 of 20 (40%) partial responders hadNSE levels <20.0 ng/ml at restaging. The mean NSE value forcomplete-remission patients was 15.3 ±1.0 ng/ml (9.9 to 20.8

ng/ml) compared with a mean of 29.1 ±4.7 ng/ml (7.5 to 94.1ng/ml) in partial-remission patients (p < 0.01). No extensive-stage-disease patient whose NSE fell to less than 20.0 ng/ml

failed to achieve a response.Relapse data are available for 23 extensive-stage-disease

patients, 19 (83%) of whom had clear elevations in serum NSEat the time of clinical relapse (see above; Chart 5). Only onepatient had a decline in the NSE at relapse, while 3 patients hadstable NSE levels. Two of the latter cases had had an elevatedpretreatment NSE which had fallen to normal at restaging andremained normal at relapse. One of the patients with stable NSEat relapse had a biopsy-proven solitary central nervous system

relapse. The remaining patients relapsed in sites of previousdisease including liver, lung, and bone (one biopsy-proven small

cell lung cancer; 2 were clinically assessed). A rise in the serumNSE preceded the clinical recognition of relapse in 10 of 18(56%) extensive-stage-disease patients for whom adequate se

ría!samples were available and did so from 2 to 12 weeks priorto the recognition of recurrent disease (mean, 6.2 weeks; Table1). Two representative cases are shown in Chart 6.

DISCUSSION

Various attempts to improve the staging and monitoring oftherapy of patients with small cell lung cancer by using one orseveral of the multiple-peptide hormones associated with this

cancer have generally met with failure (24). In part, this failure is

due to tumor heterogeneity (2). The recent work of Tapi ef a/.(27) and others (12, 18, 22, 25, 26, 31) demonstrating thepresence of NSE in a variety of neuroendocrine tumors but notin non-neuroendocrine cancers suggests that this unique isoen-

zyme of enolase may be a useful marker for small cell lungcancer. Subsequent studies (1, 4) have shown that serum NSEis elevated at diagnosis in a majority of small cell lung cancerpatients prior to treatment. Furthermore, NSE levels tended tocorrelate with tumor burden, because the highest values werefound in patients with metastatic disease while lower valuesoccurred in those with tumor confined to the chest. Importantly,NSE levels declined toward normal in patients demonstratingclinical response to chemotherapy and rose in relapsing patients.Patients with progressive disease generally had increasing NSEat restaging. In both of these previous reports, serial NSE levelswere available for only a limited number of patients. As a result,these authors had insufficient data to determine whetherchanges in serum NSE levels could predict clinical relapse or thedevelopment of chemotherapy resistance.

We also found NSE to be elevated at diagnosis in the majorityof (73%) of our patients, including 59% of the limited-stage

disease patients and 83% of those with extensive disease. NSElevels at diagnosis tended to correlate with the initial tumorburden as evidenced by increasing mean NSE values beingassociated with increasing number of metastatic sites (Chart 1).An occasional patient with limited-stage disease had a markedlyelevated NSE, and a rare patient with extensive-stage disease

had a normal value. In both circumstances, errors in stagingcould account for these discrepancies, or there may have beenan occasional error in histological diagnosis. However, since all

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Sert/m Enolase in Small Cell Lung Cancer

125

100-

75

50

E> 25

2 o

5 100

75

50

25

combinotion chemotheropy salvage chemotherapy

relapse

12 16 20 24 28 32

WEEKS OF TREATMENT

36 40 44

Chart 6. Serial NSE levels in 2 patients with extensive disease; both show arise in NSE prior to relapse. One patient (top) fails to respond to salvage chemotherapy with concomitant progressive increase of NSE. Salvage therapy haseffected a second response in the remaining patient (bottom) with an associateddecrease in NSE. Cfl. complete remission.

pathology was reviewed, the latter appears unlikely. We likewisefound a very good correlation between the patients' clinical

courses and subsequent changes in serum NSE, especially inthose individuals with elevated pretreatment values. In only 5patients did the NSE increase at restaging when a response wasobtained, while 5 responding patients maintained essentiallystable NSE levels. The remaining 40 responding patients all hada decline in NSE at restaging. Interestingly, all of the 10 responding patients (7 limited-stage disease; 3 extensive-stage disease)

with a rising or stable NSE level at restaging had had a normalor nearly normal pretreatment NSE.

Only 2 patients (one limited-stage disease; one extensive-

stage disease) had a fall in serum NSE at relapse, although 3patients (all extensive-stage disease) had stable NSE levels; the

remaining 30 relapsing patients had a definite rise in serum NSEupon tumor recurrence. A stable or declining NSE in relapsingpatients may have occurred for a number of reasons includingthe growth of tumor cells devoid of NSE, tumor cells containingNSE may have failed to release it into serum, or there may havebeen a change in histology at relapse to a non-small cell type (3,

5). The latter seems unlikely in our series since patients whowere rebiopsied at relapse had small cell lung cancer histologi-

cally. Thus, from our data, we can only conclude that NSE doesnot always increase at relapse, for reasons which are unknown.

Of particular interest are the 23 patients who had multiple NSEvalues obtained before the clinical recognition of relapse. Fifteen(65%) of these patients had a clear elevation in NSE that predated the clinical recognition of relapse by as many as 12 weeks.Importantly, every patient who achieved a partial or completeresponse accompanied by a fall in NSE and whose NSE levelsubsequently increased following restaging and cessation of

chemotherapy eventually relapsed; i.e., there were no "false-positive" increases in NSE levels.

Four limited-stage-disease patients remain in clinical complete

remission; 2 have stable and normal NSE levels at 7+ and 28+months from diagnosis. The other 2 patients, who are at 12+and 20+ months from diagnosis, have had recent slight increasesin serum NSE values but thus far have been without evidence ofrelapse for 8 and 4 weeks, respectively. Clearly, if NSE is to beuseful in the management of small cell lung cancer, this predictiveproperty is important and requires verification. The predictiveproperty of NSE resembles the behavior of carcinoembryonicantigen (29) and neurophysins (17), both of which appear toincrease in relapsing small cell lung cancer patients as many as3 months before the clinical recognition of recurrent disease.However, these and other putative markers of small cell lungcancer have been associated with a heterogeneity of expression,while NSE has thus far been found in all cell lines of small celllung cancer tested (15).

NSE has not yet been fully evaluated in patients with NSCLCalthough Marangos ef al. (15) have reported a clear distinctionin the NSE levels measured in tissue cultures of small cell lungcancer as compared with NSCLC. However, as with other enzymes originally thought to be found exclusively in neuroendo-

crine cells (6), NSE has been detected recently in a few patientswith NSCLC. Ariyoshi ef al. (1) reported elevated NSE levels in11% of 54 patients with NSCLC. Perhaps of note, all of thesepatients had either large cell lung cancer exclusively or large cellmixed with other non-small cell histologies. This is particularly

noteworthy in light of the findings of Gazdar ef al. (6, 7), whoreported in vitro "conversion" of small cell lung cancer to largecell cancer morphologically. Although "transformed" cells hadlost most or all of their "amine precursor uptake and decarbox-ylation characteristics," certain neuroendocrine features such as

creatine kinase-BB isoenzyme activity were retained. NSE was

not evaluated. Thus, it is possible that the large cell lung cancersdescribed by Ariyoshi were originally small cell tumors that"changed" histology (5) but "retained" NSE activity or were mixed

tumors (23) with the small cell component incompletely eradicated by therapy. Further work is necessary to clarify this issue.

In summary, NSE is elevated at diagnosis in a majority ofpatients with small cell lung cancer, especially those with extensive stage disease. NSE levels correlate with tumor burden andgenerally reflect the clinical course of disease falling with remission and rising with relapse. Our data suggest that, although thereturn of NSE to normal is unfortunately not an assurance oflong-term survival, its sustained normalization appears to be a

prerequisite for cure. Of equal importance is the observationthat, in two-thirds of the patients evaluated, an increase in serum

NSE actually predated the clinical recognition of relapsed disease. This latter property, if it proves reproducible, may be usefulin the future management of patients with small cell lung cancerin that it would allow for the early institution of different therapyat a time when it is likely to be most beneficial, i.e., when thetumor burden is low. While at present salvage regimens forrelapsed small cell lung cancer are lacking in sustained efficacy,the apparent synergism of cisplatin and etoposide hold promisefor more effective treatment regimens in the future (28). SerumNSE and immunoperoxidase staining also may eventually proveuseful in distinguishing small cell lung cancer from non-small cell

lung cancer in patients whose tumors are particularly anaplastic,

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D. H. Johnson et al.

defying light microscopic characterization.Further prospective studies are under way to fully define the

place of this and other potential biomarkers (7,17,21,29) in themanagement of small cell lung cancer.

ACKNOWLEDGMENTS

The authors would like to thank Alice Hammond and Nancy Settles for typingthe manuscript and to acknowledge the technical assistance of Alexandra Parma,Karen Anderson, and Karen Prater.

REFERENCES

1. Ariyoshi, Y., Kato, K., Ishiguro, Y., Ota, K., Sata, T., and Suchi, T. Evaluationof serum neuron-specific enolase as a tumor marker for carcinoma of the lung.Gann, 74:219-225,1983.

2. Baylin, S. B., Weisburger, W. R., Eggleston, J. C., Mendelsohn, G., Beaven,M. A., Abeloff, M., and Ettinger, D. S. Variable content of histaminase, i-dopadecarboxylase and calcitonin in small-cell carcinoma of the lung. N. Engl. J.Med., 299:105-110,1978.

3. Brereton, H. D., Matthews, M. J., Costa, J., Kent, H., and Johnson, R. E.Mixed anaplastia small-cell and squamous-cell carcinoma of the lung. Ann.Intern. Med., 88: 805-806,1978.

4. Carney, D. N., Marangos, P. J., Ihde, D. C., Bunn, P. A., Cohen, M. H., Minna,J. D., and Gazdar, A. F. Serum neuron-specific enolase: a marker for diseaseextent and response to therapy of small-cell lung cancer. Lancet, 1:583-585,

1982.5. Fer, M. F., Grosh, W. W., and Greco, F. A. Morphologie changes in small cell

lung cancer. In: F. A. Greco (ed.), Biology and Management of Lung Cancer,pp. 109-123. Boston: Martinus Nijhoff Publishers, 1983.

6. Gazdar, A. F., Carney, D. N., Guccion, J. G., and Baylin, S. B. Small cellcarcinoma of the lung: cellular origin and relationship to other pulmonarytumors. In: f. A. Greco, P. A. Bunn, and R. K. Oldham (eds.), Small Cell LungCancer, pp. 145-175. New York: Gruñeand Stratton, 1981.

7. Gazdar, A. F., Zweig, M. H., Carney, D. N., Van Steirteghen, A. C., Baylin, S.B., and Minna, J. D. Levels of creatine kinase and its BB isoenzyme In lungcancer specimens and cultures. Cancer Res., 41: 2773-2777,1981.

8. Goslin, R. H., Skarin, A. T., and Zamcheck, N. Carcinoembryonic antigen. Auseful monitor of therapy of small cell lung cancer. J. Am. Med. Assoc., 246:2173-2176,1981.

9. Greco, F. A., Hände,K. R., Richardson, R. L, and Oldham, R. K. High-dose

methotrexate in combination chemotherapy for small cell lung cancer. RecentResults Cancer Res., 74: 50-55,1980.

10. Greco, F. A., and Oldham, R. K. Small-cell lung cancer. N. Engl. J. Med., 307:355-358,1979.

11. Greco, F. A., Richardson, R. L, Snell, J. p., Stroup, S. L, and Oldham, R. K.Small cell lung cancer. Complete remission and improved survival. Am. J.Med., 66: 625-630, 1979.

12. Gu, J., Polak, J. M., Van Noorden, S., Pearce, A. G. E., Marangos, P. J., andAzzopardi, J. G. Immunostaining of neuron-specific enolase as a diagnostictool for Merkel cell tumors. Cancer (Pnila.), 52:1039-1043,1983.

13. Hande, K. R., Oldham, R. K., Fer, M. F., Richardson, R. L., and Greco, F. A.Randomized study of high-dose versus low-dose methotrexate in the treatment

of extensive small cell lung cancer. Am. J. Med., 73: 413-419,1982.14. Ihde, D. C., Makuch, R. W., Carney, D. N., Bunn, P. A., Cohen, M. H.,

Matthews, M. J., and Minna, J. D. Prognostic implications of stage of diseaseand sites of métastasesin patients with small cell carcinoma of the lung treatedwith intensive combination chemotherapy. Am. Rev. Respir. Dis., 723: 500-507,1981.

15. Marangos, P. J., Gazdar, A. F., and Carney D. N. Neuron specific enolase inhuman small cell carcinoma cultures. Cancer Lett., 75: 67-71,1982.

16. Marangos, P. J., Zis, A. P., Clark, R. L., and Goodwin, F. K. Neuronal, nonneuronal and hybrid forms of enolase in the brain: structural, immunologicaland functional comparisons. Brain Res., 750:117-133,1978.

17. North, W. G., Maurer, L. H., and O'Donnell, J. F. The neurophysins and small

cell lung cancer. In: F. A. Greco (ed.), Biology and Management of LungCancer, pp. 143-169. Boston: Martinus Nijhoff Publishers, 1983.

18. Odelstad, L., Pahlman, S., Lackgren, G., Larsson, E., Grotte, G., and Nilsson,K. Neuron specific enolase: a marker for differential diagnosis of neuroblastomaand Wilm's tumor. J. Pediat. Surg., 77: 381-385,1982.

19. Oldham, R. K., and Greco, F. A. Small-cell lung cancer. A curable disease.Cancer Chemother. Pharmacol., 4:173-177,1980.

20. Parma, A. M., Marangos, P. J., and Goodwin, F. K. A more sensitive radioim-munoassay for neuron-specific enolase (NSE) suitable for cerebrospinal fluiddetermination. J. Neurochem., 36:1093-1097,1981.

21. Pert, C. B., and Schumacher, U. K. Plasma bombesin concentrations in patientswith extensive small cell carcinoma of the lung. Lancet, 7: 509,1982.

22. Prinz, R. A., and Marangos, P. J. Use of neuron-specific enolase as a serummarker for neuroendocrine neoplasms. Surgery, 93: 887-889,1982.

23. Radice, P. A., Matthews, M. J., Ihde, D. C., Gazdar, A. F., Carney, D. N.,Bunn, P. A., Cohen, M. H., Fossieck, B. E., Makuch, R. W., and Minna, J. D.The clinical behavior of "mixed" small cell/large cell bronchogenic carcinomacompared to "pure" small cell subtypes. Cancer (Phila.), 50:2894-2902,1982.

24. Richardson, R. L., Greco, F. A., Oldham, R. K., and Liddle, G. W. Tumorproducts and potential markers in small cell lung cancer. Semin. Oncol., 5:253-262,1978.

25. Schmechel, 0. E., and Marangos, P. J. Neuron specific enolase (NSE): specificcellular and functional marker for neuron and neuronendocrine cells. In: J. L.Barker, and J. F. McKelvy (eds.), Current Methods in Cellular Neurobiology,pp. 1-63. New York: John Wiley & Sons, Inc., 1983.

26. Schmechel, D., Marangos, P. J., and Brightman, M. Neuron-specific enolaseis a molecular marker for peripheral and central neuroendocrine cells. Nature(Lond.) 276: 834-836,1978.

27. Tapia, F. T., Polak, J. M., Barbosa, A. J. A., Bloom S. R., Marangos, P. J.,Dermody, C., and Pearse, A. G. E. Neuron-specific enolase is produced byneuroendocrine tumours. Lancet, 7: 808-811,1981.

28. Tinstey, R., Comis, R., DiRno, S., Ginsberg, S., Quito, J., Htekes, R., Poiesz,B., Rudolph, A., Issell, B., and Lee, F. Potential clinical synergy observed inthe treatment of small cell lung cancer (SCLC) with cispiatin (P) and VP-16-213 (V). Proc. Am. Soc. Clin., Oncd., 2:198,1983.

29. Waalkes, T. P., Abeloff, M. D., Woo, K. B., Ettinger, D. S., Ruddon, R. W.,and Aldenderfer, P. Carcinoembryonic antigen for monitoring patients withsmall cell carcinoma of the lung during treatment. Cancer Res.. 40: 4420-4427,1980.

30. Wolff. S. N., Johnson, D. H., Hande, K. R., Hainsworth, J. D., and Greco, F.A. High-dose etoposide as single-agent chemotherapy for small cell carcinomaof the lung. Cancer Treat. Rep., 67:957-958,1983.

31. Zelter, P. M., Marangos, P. J., Parma, A. M., Sather, H., Dalton, A., Hammond,D., Siegel, S. E., and Seeger, R. C. Raised neuron-specific enolase in serumof children with metastatic neuroblastoma. Lancet, 2: 361-363,1983.

5414 CANCER RESEARCH VOL. 44

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