Paclitaxel/ifosfamide or navelbine/ifosfamide chemotherapy for advanced non-small cell lung cancer: CALGB 9532.

In order to explore non-cisplatin containing regimens for advanced non-small cell lung cancer, Cancer and Leukemia Group B conducted a randomized Phase-II study of two novel combinations, paclitaxel/ifosfamide and vinorelbine/ifosfamide. Both regimens were active with a 38% response rate (95% CI: 24%, 53%) and 31% (95% CI: 18%, 47%), respectively. Median survivals were 8.5 and 7.4 months. Toxicity, mostly neutropenia, was acceptable. These two combinations establish a 'proof of principle' that non-cisplatin containing regimens also have activity in this setting.

Small-cell lung cancer: treatment progress and prospects.

Although small-cell lung cancer (SCLC) represents only 20% of all lung cancer cases in the United States, it is the most lethal subtype. Combination chemotherapy unequivocally offers the best chance for improved survival in SCLC. Either PE (platinum plus etoposide) or CAV (cyclophosphamide, Adriamycin, and vincristine) is a reasonable first-line therapy. Alternating PE with CAV does not appear to be significantly superior to PE or CAV alone. Increasing dose intensity, although sometimes associated with higher response rates, does not appear to significantly improve survival and should not be used outside of a clinical study. Several new agents with novel mechanisms of action show promise in treating SCLC. These include: gemcitabine (Gemzar), paclitaxel (Taxol), docetaxel (Taxotere), topotecan (Hycamtin), and irinotecan (Camptosar). Given the poor survival and response rates in relapsed patients and the chemoresponsiveness of SCLC, patients with newly diagnosed extensive disease should be encouraged to enroll in phase I or II trials. Thoracic radiotherapy confers a small survival advantage in limited-stage SCLC patients. Although prophylactic cranial irradiation does not significantly improve survival, it does reduce central nervous system (CNS) recurrences with minimal long-term sequelae. Surgery should be considered only for: (1) resection of a solitary pulmonary nodule, which must be followed by adjuvant chemotherapy; and (2) resection of an unresponsive chest tumor, which may harbor a non-small-cell lung cancer component.

Alternating MOPP and ABVD chemotherapy plus mantle-field radiation therapy in patients with massive mediastinal Hodgkin's disease.

PURPOSE: To evaluate the efficacy and toxicity of mechlorethamine, vincristine, procarbazine, and prednisone (MOPP)/doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) chemotherapy plus mantle-field radiation therapy in the treatment of patients with massive mediastinal Hodgkin's disease of any stage. PATIENTS AND METHODS: Eighty patients presented with Hodgkin's disease and a mediastinal mass greater than one third the greatest chest diameter on chest radiograph. Patients were staged and treated with MOPP alternated with ABVD chemotherapy for a total of six cycles. Patients then received 10 Gy mantle-field radiation therapy delivered to the original extent of disease followed by 25 to 35 Gy to the residual abnormalities. RESULTS: The complete response (CR) rate was 89%. With a median follow-up duration of 10 years, disease-free survival of the complete responders is 78% at 15 years and overall survival is 75% at 15 years. For patients with stage I or II disease, disease-free survival was 76% at 15 years and overall survival was 79%; for those with stage III or IV disease, disease-free survival was 82% at 15 years and overall survival was 64%. Age, stage, sex, B symptoms, number of extranodal sites, lactate dehydrogenase (LDH) levels, erythrocyte sedimentation rate, and platelet count did not influence treatment outcome. Treatment-related pneumonitis was noted in 16% of patients (fatal in one), mainly in those older than age 35 years who received total doses of radiation therapy greater than 42 Gy. Fertility is more often preserved with MOPP/ABVD therapy than with MOPP chemotherapy and there appears to be less pulmonary and cardiac disease than with ABVD chemotherapy. Two patients have developed second solid tumors within radiation ports and one relapsed patient developed acute leukemia after MOPP salvage therapy. CONCLUSION: MOPP/ABVD followed by mantle-field radiation therapy is an effective treatment for all stages of Hodgkin's disease that present with a large mediastinal mass. Our data suggest that the large mediastinal mass is a more dominant determinant of prognosis than Ann Arbor stage or other clinical prognostic factors.

Outcome of patients with small-cell lung cancer during 20 years of clinical research at the US National Cancer Institute.

OBJECTIVE: To determine the outcome of all patients with small-cell lung cancer (SCLC) treated at the US National Cancer Institute between April 1973 and April 1993. DESIGN: We retrospectively analyzed a series of 594 consecutive patients with SCLC treated at a single institution during a 20-year period to assess changes in duration of survival and toxicity related to various treatment regimens. MATERIAL AND METHODS: For analysis, patients were grouped by decade, and the duration of survival of patients with limited- and extensive-stage SCLC was examined to assess whether patients treated during the first decade of the study (1973 through 1983), when cyclophosphamide-based regimens were used, had different outcomes than those treated during the second decade (1983 through 1993), when cisplatin-based regimens were used. Patients had a minimal follow-up of 2 years. RESULTS: No significant difference was found in the survival of patients with limited- or extensive-stage SCLC treated during the second decade in comparison with during the first decade of the study. Among patients with extensive-stage SCLC, performance status 3 or 4 and metastatic lesions of the liver and central nervous system had a significant adverse effect on survival in both the first and the second decade. Among patients with limited-stage disease, performance status 3 or 4 had the most significant adverse influence on survival during the overall study period. In addition, in a multivariate analysis, etoposide-cisplatin plus twice-daily chest radiotherapy was significantly associated with prolonged survival (P = 0.003). CONCLUSION: We noted no significant change in the duration of survival of patients with either limited-or extensive-stage SCLC treated at our institution during a 20-year period. A multivariate analysis showed that patients with limited-stage SCLC given a cisplatin-based regimen plus chest radiotherapy lived modestly longer than similar patients given cyclophosphamide regimens at our institution. No evidence was found of changes in pretreatment factors that would affect survival.

Survival of patients with limited-stage small cell lung cancer treated with individualized chemotherapy selected by in vitro drug sensitivity testing.

Our purpose was to study the feasibility of determining individualized chemotherapy regimens by in vitro drug sensitivity testing (DST) for patients with limited-stage small cell lung cancer (SCLC) and to evaluate patient response and survival. Fifty-four previously untreated patients with limited-stage small cell cancer were studied. Fresh tumor specimens for DST were collected, when possible, from patients' biopsies before the start of treatment. The differential staining cytotoxicity assay was used to determine the in vitro sensitivity of the tumor cells to different drugs. From these results, an in vitro best regimen (IVBR), a three-drug combination of previously proven efficacy of seven active drugs in SCLC, was selected. Patients were initially treated with four cycles of etoposide/cisplatin and concurrent radiotherapy. This was followed by four cycles of either individualized chemotherapy regimens based on the results of DST or, when DST results were not available, four cycles of vincristine, doxorubicin, and cyclophosphamide. Eighteen patients (33%) underwent biopsy procedures that provided tissue specimens for DST. The biopsy specimens contained tumor cells in 16 of 18 patients. The median duration from diagnosis to start of treatment was 22 days (range, 4-58 days) for the 18 patients who underwent elective thoracic biopsies compared to 21 days (range, 2-74 days) for members of the group that did not (P2 = 0.58). Time from thoracic biopsy to initiation of chemotherapy was a median of 4 days (range, 2-22 days). DST was done in 10 patients, and IVBR was administered to 8 patients. The median actuarial survival of 8 patients treated with their IVBR was 38.5 months compared to 19 months for the 46 patients treated with empiric chemotherapy. Selection of individualized chemotherapy regimens is labor intensive but feasible in limited-stage SCLC. Treatment with an individualized IVBR in our patients was associated with prolonged patient survival; however, because of the nature of our study design, other factors could have affected the results.

Practical issues in the management of the patient with small cell lung cancer.

Small cell lung cancer (SCLC) accounts for 20% of all lung cancers. More than two thirds of patients with SCLC present with clinically evident distant metastases. Patients with limited stage disease are treated with a combination of chemotherapy and chest radiation. Patients with extensive stage disease and good performance status are candidates for combination chemotherapy. Almost all patients relapse after an initial response. This article focuses on the common sense approach to the management of SCLC.

Patients with limited-stage small-cell lung cancer treated with concurrent twice-daily chest radiotherapy and etoposide/cisplatin followed by cyclophosphamide, doxorubicin, and vincristine.

PURPOSE: A phase II trial in patients with limited-stage small-cell lung cancer treated with induction etoposide/cisplatin plus twice-daily chest radiotherapy was conducted in an attempt to increase response rates and prolong survival. PATIENTS AND METHODS: Fifty-four previously untreated patients with limited-stage small-cell cancer were treated with etoposide/cisplatin and concurrent radiotherapy at 1.5 Gy twice daily for 3 weeks to a total dose of 45 Gy. Patients then received three more cycles of etoposide/cisplatin followed by four cycles of vincristine, doxorubicin, and cyclophosphamide or an individualized chemotherapy regimen. RESULTS: Nine patients are alive and free of cancer a median of 4 years (range, 2 to 7) from the start of treatment. Thirty-eight have had progression of their cancer at a median of 1.2 years (range, 0.5 to 5.4) and all have died of small-cell cancer. Thirteen of these 38 patients' (34%) only site of initial relapse was in the CNS and all died of CNS metastases. Five patients died during therapy or from its complications and two patients died of causes other than relapsed small-cell lung cancer and toxicity. The median survival time is 21.3 months, with an actual survival rate of 83% at 1 year, and actuarial survival rates of 43% at 2 years and 19% at 5 years. CONCLUSION: This combined modality regimen for patients with limited-stage small-cell lung cancer results in a 2-year survival rate of 43%, but the principal cause of death in these patients is still relapse of the original cancer. Isolated CNS metastases caused more than 30% of the cancer deaths.

NCI-Navy Medical Oncology Branch cell line data base.

The cell line data base described in this paper includes both clinical information about the patients from whom the cell lines were derived and information about the in vitro analyses performed of the cell lines. The cell line data base has evolved as a part of a systematic effort by a research group at the NCI since 1976 to generate human cell lines as biological tools to study cancer and other diseases. The cell lines were generated from clinical specimens obtained as part of a series of Institutional Review Board-approved clinical protocols. The preponderance of the data is on lung cancer cell lines, though a broad range of other cancers are represented. A bank of over 300 human cell lines including cancer cell and in some instances autologous B-lymphoblastoid cells from the NCI-VA and NCI-Navy Medical Oncology Branch are reposited at the American Type Culture Collection. The cell lines are available for the research community. The entire data base is available on the American Type Culture Collection Web Site (WWW:http:@www.atcc.org/).

Correlation of in vitro drug sensitivity testing results with response to chemotherapy and survival: comparison of non-small cell lung cancer and small cell lung cancer.

Clinical protocols for small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) were devised to prospectively select individualized chemotherapy based on in vitro drug sensitivity testing (DST) of cell lines derived from the patient's SCLC tumor cell lines or the patient's fresh NSCLC tumor. DST data derived from SCLC tumor cell lines were available for 33/115 (29%) patients. The DST-selected chemotherapy regimen was administered to 21 (18%) patients, or 64% of patients with DST. In SCLC< the DST-selected chemotherapy was administered either during weeks 13-24 following 12 weeks of etoposide/cisplatin, or at relapse after complete response to etoposide/cisplatin. Several parameters of in vitro drug sensitivity were significantly associated (two-sided P < 0.05) with clinical response to primary therapy and also with response to the DST-selected chemotherapy regimen, but were not associated with survival (P = 0.24). Five patients treated with their DST-selected chemotherapy attained a complete or partial response, compared to 5 of 68 who received an empiric regimen (P = 0.057). A total of 36/165 (22%) NSCLC patients had DST successfully completed. These results directed management for 21/96 (22%) patients who eventually received chemotherapy, or 58% of patients with DST. Response to chemotherapy for the patients treated prospectively with their DST-selected chemotherapy regimen (2/21; 9%) was not significantly different than the response rate for patients treated empirically with etoposide/cisplatin (10/69; 14%) in the absence of in vitro results to direct chemotherapy (P = 0.73). There was no difference in survival by treatment group for the NSCLC patients. The correlation between in vitro and clinical response was not significant for any individual drug or for all drugs considered together, illustrating the poor predictive value of in vitro testing with currently available chemotherapy in NSCLC.

MYC family DNA amplification in 126 tumor cell lines from patients with small cell lung cancer.

We identified 126 tumor cell lines established from patients with small cell cancer at the NCI-Navy Medical Oncology Branch from 1977 through 1992. Extensive clinical information was available on 96 patients from whom these cell lines were established. These patients comprised approximately one fourth of the 407 patients treated on prospective therapeutic clinical trials during the same time period. The proportion of tumor cell lines established from previously untreated patients with both limited and extensive stage small cell lung cancer increased during the 16 years of the study (P = 0.008). MYC family DNA amplification was present in 16 of 44 (36%) tumor cell lines established from previously treated patients compared to 7 of 52 (11%) of tumor cell lines established from untreated patients (P = 0.009). MYC DNA amplification in tumor cell lines established from patients previously treated with chemotherapy continued to be associated with shortened survival (P = 0.001). The initiation of a policy to obtain tumor tissue for the purpose of selecting chemotherapeutic agents given to individual patients was associated with an increase in the proportion of patients from whom tumor cell lines could be established for both extensive and limited stage patients (P = 0.0001 and 0.05, respectively).

Small cell lung cancer. State-of-the-art therapy 1994.

In the United States, small cell lung cancer (SCLC) accounts for about 20% of all cases of lung cancer. Without treatment, tumor progression in patients with SCLC is rapid, with a median survival of 2 to 4 months. Modern chemotherapy has yielded multifold increases in median survival, but only minimal improvements have occurred over the last decade. Combination chemotherapy with etoposide/cisplatin prolongs survival, especially in patients with limited disease. In patients at high risk of toxicity from standard combination chemotherapy, single-agent chemotherapy may have a viable role, but whether its efficacy is comparable to combination regimens must be established in clinical trials. Clearly, new, more effective drugs will be required for any major improvements in the treatment of SCLC. Combined-modality therapy employing chemotherapy and chest irradiation appears to produce excellent cytotoxic effects and is relatively well tolerated in patients with limited disease. A recent meta-analysis of 13 randomized trials showed a modest but significant 14% reduction in the relative mortality rate of patients receiving chemotherapy/chest irradiation vs those receiving chemotherapy alone. Surgery as sole treatment can produce cures in highly selected patients with limited disease and can reduce the rate of local recurrence. The use of surgery after definitive treatment remains experimental and should not be considered other than in controlled clinical trials.

Obesity and therapy-related toxicity in patients treated for small-cell lung cancer.

BACKGROUND: Obese individuals have altered pharmacokinetics for many medications when compared with the non-obese. For the oncologist treating an obese cancer patient, these changes in drug disposition may potentially cause increased therapy-related toxicity. As a consequence, oncologists frequently treat obese patients with dose reductions in an effort to decrease chemotherapy toxicity. However, little clinical data exist to either support or refute this policy. PURPOSE: The clinical course of a cohort of patients treated for small-cell lung cancer (SCLC) was evaluated to determine if the obese patients had an increase in therapy-related toxicity. METHODS: The study sample included 262 patients with histologically confirmed SCLC treated in clinical trials from 1977 through 1993. Before 1986, patients with limited stage SCLC were treated with a cyclophosphamide-based regimen with (n = 47) or without (n = 46) chest radiotherapy. Subsequent patients with limited stage disease (n = 54) received etoposide and cisplatin plus twice-daily chest radiotherapy. Patients with extensive stage SCLC were randomly treated with standard-dose (n = 46) or high-dose etoposide plus cisplatin (n = 44); poor-risk patients with extensive stage disease (n = 25) were assigned to standard dose etoposide plus cisplatin. For all patients, actual body weight was used when determining initial doses of chemotherapy. The measure of relative weight was the body mass index (BMI), which was calculated from the pretreatment height and weight data. The BMI was evaluated both on a continuum and with patients grouped into BMI levels (normal, obese, and severely obese). Toxicity parameters were collected during induction chemotherapy and were compared with the BMI. In addition, the overall survival of the entire cohort was evaluated, with patients divided into different groups based on their BMI level. RESULTS: We performed 170 comparisons between the BMI as a continuum or the BMI level and the 15 toxicity parameters. There were no consistent associations of significance found between increasing BMI or BMI levels and increasing toxicity from therapy. When survival was evaluated, no statistically significant differences were found between the survival of patients within the different BMI levels. CONCLUSIONS: In this group of 262 patients with SCLC, obesity at the start of treatment was not associated with increased toxicity from treatment or a shortened survival. No support for empiric chemotherapy dose reductions based on ideal body weight was evident from this study.

Prospective randomized comparison of high-dose and standard-dose etoposide and cisplatin chemotherapy in patients with extensive-stage small-cell lung cancer.

PURPOSE: We performed a prospective randomized clinical trial to determine whether higher doses of etoposide and cisplatin (EP) yield more complete responses or longer survival in small-cell lung cancer (SCLC) patients. PATIENTS AND METHODS: Ninety patients with previously untreated extensive-stage SCLC fulfilled criteria for randomization to standard-dose versus high-dose EP. Another 25 patients at risk of excessive toxicity from high-dose treatment were given standard-dose therapy. During cycles 1 and 2 of EP, patients on standard-dose treatment received intravenous etoposide 80 mg/m2 on days 1 to 3 and cisplatin 80 mg/m2 on day 1 every 3 weeks; high-dose treatment consisted of etoposide 80 mg/m2 on days 1 to 5 and cisplatin 27 mg/m2 on days 1 to 5 every 3 weeks. All patients received standard-dose EP in cycles 3 and 4. In cycles 5 through 8, completely responding patients continued standard-dose EP; all other patients received either cyclophosphamide, doxorubicin, and vincristine, or (if possible) a combination drug program based on in vitro drug sensitivity testing of tumor-cell lines established from individual patients. RESULTS: Despite 68% higher doses and a 46% higher dose-rate intensity actually given to patients randomized to receive high-dose relative to those randomized to receive standard-dose EP, complete response rates (23% v 22%; P = .99) and median survival durations (10.7 and 11.4 months, respectively; P = .68) were virtually identical. Complete responses occurred in 4% of patients and the median survival duration was 5.8 months in nonrandomized patients. Leukopenia (P < .0001), thrombocytopenia (P < .0001), febrile neutropenia (P = .01), and weight loss (P = .02) were significantly more common in patients randomized to receive high-dose compared with standard-dose EP. CONCLUSION: No therapeutic benefits resulted from increasing planned doses by 67% for the first two cycles of EP in patients with extensive-stage SCLC. Higher doses were associated with substantially worse toxicities.

Phase II trial of fludarabine phosphate and interferon alfa-2a in advanced mycosis fungoides/Sézary syndrome.

PURPOSE: This phase II study was undertaken to assess the efficacy and toxicity of the addition of continuous low-dose interferon alfa-2a (IFN) to fludarabine in patients with advanced or refractory mycosis fungoides (MF) or the Sézary syndrome (SS). PATIENTS AND METHODS: Thirty-five patients were treated with fludarabine 25 mg/m2 intravenously (IV) on days 1 to 5 every 28 days along with IFN 5 x 10(6) U/m2 subcutaneously three times per week continuously for up to eight cycles. IFN doses were escalated to 7.5 x 10(6)/m2 at day 29 if constitutional toxicities were less than grade 3. Twenty-one patients had not responded to prior chemotherapy or total-skin electron-beam irradiation (TSEB), and 10 of these had received prior deoxycoformycin (pentostatin; DCF) and intermittent high-dose IFN; seven had received only topical therapies, and seven were untreated. RESULTS: Four patients achieved a complete response (CR) and 14 achieved a partial response (PR) for an overall response rate of 51% (95% confidence interval, 35% to 70%). Four of 11 patients with visceral involvement responded. The median progression-free survival duration of the patients who responded was 5.9 months, and three of the complete responders are in unmaintained response after 18 to 35 months. Grade 3 or 4 hematologic toxicity occurred in 21 patients, including two who developed persistent bone marrow aplasia. Eighteen patients developed infections during therapy, including five with herpes zoster, one with Pneumocystis carinii, one with extrapulmonary tuberculosis, and two with disseminated toxoplasmosis. CONCLUSION: The combination of fludarabine with continuous low-dose IFN is an active regimen in patients with advanced MF/SS, including patients with visceral involvement and patients who progressed after prior therapy with DCF and IFN. This regimen has induced unmaintained remissions in a small subset of patients.

Effect of thoracic radiotherapy on mortality in limited small cell lung cancer. A meta-analysis of 13 randomized trials among 2,140 patients.

This meta-analysis was designed to evaluate the hypothesis that thoracic radiotherapy contributes to a moderate increase in overall survival in limited small-cell lung cancer. We collected individual data on all patients enrolled before December 1988 in randomized trials comparing chemotherapy alone with chemotherapy combined with thoracic radiotherapy. The study included 13 trials and 2140 patients with limited disease. A total of 433 patient with extensive disease were excluded. Overall, 1862 of 2103 patients who could be evaluated died; the median follow-up period for the surviving patients was 43 months. The relative risk of death in the combined therapy group as compared with the chemotherapy group was 0.86 (95 percent confidence interval, 0.78 to 0.94; P = 0.001), corresponding to a 14 percent reduction in the mortality rate. The benefit in terms of overall survival at three years (+/- SD) was 5.4 +/- 1.4 percent. Indirect comparison of early with late radiotherapy and of sequential with non-sequential radiotherapy did not reveal any optimal time for treatment. There was a trend toward a larger reduction in mortality among younger patients. In conclusion, thoracic radiotherapy moderately improves overall survival in patients with limited small-cell lung cancer who are treated with combination chemotherapy.

Calcitonin elevation in small cell lung cancer without ectopic production.

To determine the relative contribution of ectopic calcitonin (CT) production versus nonectopic secretion of CT in patients with small cell lung cancer (SCLC), serum and urine immunoreactive CT (iCT) levels of 86 different subjects were measured by radioimmunoassay (RIA) using two polyclonal antisera (Ab3b and Ab4). The subjects included 49 previously untreated patients with SCLC, 17 smokers, and 20 nonsmokers. Serum and urine iCT values were highest in the patients with SCLC, intermediate in the smokers, and lowest in the nonsmokers (p < 0.0003). Sixteen of the 49 patients with SCLC had tumor cell lines available for determination of CT mRNA expression by RNase protection assay (RPA) and iCT production by RIA. CT mRNA was detected in nine of 16 subjects and iCT in eight of 16. The tumor cell lines of seven patients had undetectable CT by both RPA and RIA, and of these, five had elevated urine or serum iCT values compared with those of nonsmokers, and two had levels above all values in the smoker group. Immunohistochemical staining of formalin-fixed, paraffin-embedded tumor samples detected iCT in two of four tumors from patients whose tumor cell lines had CT mRNA by RPA and iCT by RIA, but in none of six whose tumor cell lines had undetectable CT mRNA. Thus, increased iCT values in some patients with SCLC are likely due to sources other than CT production by tumor cells.

Individualized chemotherapy for patients with non-small cell lung cancer determined by prospective identification of neuroendocrine markers and in vitro drug sensitivity testing.

We attempted to prospectively select individualized chemotherapy for 165 non-small cell lung cancer patients based on in vitro analysis of neuroendocrine (NE) markers and drug sensitivity testing (DST) using fresh tumor. The chemotherapy used for small cell lung cancer (SCLC) was selected when NE marker expression determined by L-dopa decarboxylase assay was documented. Selection of chemotherapy for other patients was guided by DST results using a modified dye exclusion assay when available; otherwise etoposide and cisplatin was administered. A total of 112 of 165 (68%) specimens were assayed for L-dopa decarboxylase and 36 patients (22%) had DST. In vitro data directed management for 27 of 96 (28%) patients given chemotherapy: 6 with NE markers were treated with the SCLC regimen; and 21 (58% of those with DST) received their DST-selected chemotherapy regimen. There were no significant differences in response rate among all 3 treatment arms (P = 0.076). However, response to chemotherapy for the patients treated prospectively with a SCLC regimen was 3 of 6 (50%), marginally better than patients given their DST-selected chemotherapy regimen (2 of 21; 9%; P = 0.056) or those treated with etoposide and cisplatin (10 of 69; 14%; P = 0.061). When patients whose NE markers were identified retrospectively are included, 4 of 9 (44%) responded to administered chemotherapy, compared to 7 of 55 (13%) with no NE markers present (P = 0.04). There were no differences in survival among the three treatment groups. Cisplatin and etoposide comprised the most active regimen in vitro for tumors from 16 of 36 (44%) patients, potentially limiting the benefit of DST since this is often the empiric therapy for non-SCLC. Furthermore, the correlation between in vitro and clinical response is nonsignificant for all drugs tested, highlighting the overall relative resistance of non-SCLC tumors to currently available chemotherapy.