Little to learn from phase II trials in small-cell lung cancer

Small cell lung cancer: state of the art and future perspectives

Small cell lung cancer accounts for less than 20% of all lung cancer. The management of this distinct tumor entity differs from the more common non-small cell lung cancer. Primary prevention of smoking exposure remains the most important public health measure. Although small cell lung is an exquisitely chemosensitive disease it remains ultimately fatal for the great majority of patients. Combination chemotherapy regimens have improved response rate and survival of the last three decades. The combination of cisplatin and etoposide has been considered the standard therapy for over a decade. More intensive triplet combination chemotherapy and high-dose chemotherapy have shown improved response rates and survival. Early concomitant and accelerated radiotherapy improves survival in limited stage disease. This review summarizes the current state of the art and future perspectives in detection, staging and standard therapy of small cell lung cancer. Particular emphasis is given to the importance of concomitant and accelerated radiotherapy and consideration of dose-intensive combination chemotherapy regimens.

Long-term results of induction chemotherapy followed by concurrent chemotherapy and thoracic irradiation in limited small cell lung cancer

BACKGROUND

Small cell lung cancer (SCLC) is a chemoresponsive tumor but overall survival remains poor even in limited disease (LD). With the aim of eradicating chemoresistant tumor cells and reducing toxicity, we investigated in this phase II trial the feasibility and outcome of a sequential approach of induction chemotherapy (CT) followed, in responding patients with LD-SCLC, by intensified platinum-based CT and concurrent thoracic irradiation (TI).

MATERIALS AND METHODS

We treated 55 consecutive LD-SCLC patients with three 21-day cycles of cyclophosphamide, epiadriamycin and vincristine (CEV) as induction CT. In 44 (80%) patients there was an objective response and they received treatment intensification consisting of TI and concomitant CT with carboplatin and etoposide plus recombinant granulocite colony stimulating factor. Twenty-five (57%) patients were submitted to twice-daily thoracic irradiation (TDTI; 1.5 Gy per fraction, to a total dose of 45 Gy) and 19 (43%) to once-daily thoracic irradiation (ODTI; 2 Gy per fraction, to a total dose of 50 Gy).

RESULTS

Median follow up was 75 months (range, 42-102). Of 44 patients submitted to intensification with TI plus CT, 32 (73%) had a complete and 12 (27%) a partial response. Median overall survival of all 55 patients was 17 months with actuarial survival probabilities of 2 and 5 years, 32 and 25%, respectively. Analysis of patient sub-groups showed a 5-month median survival in non-responders, 19 in TDTI and 17 in ODTI patients, respectively. Two and 5 year survival probabilities were 0% in non-responders, 40 and 35% in TDTI and 39 and 21% in ODTI patients, respectively. At present, 13 of 44 responders are still alive, of which nine (20%) have been progression-free from 45 to 93 months (median 60). Treatment failure was registered in 31 (70%) of 44 patients who received both induction and intensification treatment. One-half of patients had intrathoracic recurrence, eight of which only local and the remaining seven local and distant. Fourteen (32%) patients had brain metastases. Grade 3-4 neutropenia occurred in 24 (55%) patients with no differences between treatment groups. Grade 3 esophagitis was registered in four (9%) patients: in 3/25 (12%) and 1/19 (5%) of those who received TDTI and ODTI, respectively (P=not significant). Acute radiation pneumonitis occurred in three (12%) patients submitted to TDTI. No clinically debilitating pulmonary fibrosis, permanent esophageal stricture or toxic death was observed.

CONCLUSIONS

In LD-SCLC patients late concurrent CT plus TI is feasible and effective. Our long-term results are similar to the best reported in the literature. Despite the high incidence of complete response obtained, however, one-half of the patients had intrathoracic relapse and one-third brain metastases.