General Information

Note: Estimated new cases and deaths from lung cancer (small cell and non-small cell combined) in the United States in 2005:[1]

• New cases: 172,570.
• Deaths: 163,510.

Without treatment, small cell carcinoma of the lung has the most aggressive clinical course of any type of pulmonary tumor, with median survival from diagnosis of only 2 to 4 months. Compared with other cell types of lung cancer, small cell carcinoma has a greater tendency to be widely disseminated by the time of diagnosis but is much more responsive to chemotherapy and irradiation.

Because patients with small cell lung cancer tend to develop distant metastases, localized forms of treatment, such as surgical resection or radiation therapy, rarely produce long-term survival.[2] However, with incorporation of current chemotherapy regimens into the treatment program, survival is unequivocally prolonged, with at least a 4- to 5-fold improvement in median survival compared with patients who are given no therapy. Furthermore, about 10% of the total population of patients remains free of disease over 2 years from the start of therapy, the time period during which most relapses occur. However, even these patients are at risk of dying from lung cancer (both small and non-small cell types).[3] The overall survival at 5 years is 5% to 10%.[3-5]

Limited-stage disease

At the time of diagnosis, approximately 30% of patients with small cell carcinoma will have tumor confined to the hemithorax of origin, the mediastinum, or the supraclavicular lymph nodes. These patients are designated as having limited-stage disease, and most 2-year disease-free survivors come from this group. In limited-stage disease, median survival of 16 to 24 months with current forms of treatment can reasonably be expected.[6-8] A small proportion of patients with limited-stage disease may benefit from surgery with or without adjuvant chemotherapy; these patients have an even better prognosis.

Extensive-stage disease

Patients with tumors that have spread beyond the supraclavicular areas are said to have extensive-stage disease and have a worse prognosis than patients with limited-stage disease. Median survival of 6 to 12 months is reported with currently available therapy, but long-term disease-free survival is rare.

Prognostic factors

The pretreatment prognostic factors that consistently predict for prolonged survival include good performance status, female gender, and limited-stage disease.[4,9,10] Patients with involvement of the central nervous system or liver at the time of diagnosis have a significantly worse outcome.[4,9-11] In general, patients who are confined to bed tolerate aggressive forms of treatment poorly, have increased morbidity, and rarely attain 2-year disease-free survival; however, patients with poor performance status can often derive significant palliative benefit and prolongation of survival from treatment.

Regardless of stage, the current prognosis for patients with small cell lung cancer is unsatisfactory even though considerable improvements in diagnosis and therapy have been made over the past 10 to 15 years. All patients with this type of cancer may appropriately be considered for inclusion in clinical trials at the time of diagnosis. Information about ongoing clinical trials is available from the NCI Web site.

References

1. American Cancer Society.: Cancer Facts and Figures 2005. Atlanta, Ga: American Cancer Society, 2005. Also available online. Last accessed May 20, 2005. 
2. Prasad US, Naylor AR, Walker WS, et al.: Long term survival after pulmonary resection for small cell carcinoma of the lung. Thorax 44 (10): 784-7, 1989.  [PUBMED Abstract]
3. Johnson BE, Grayson J, Makuch RW, et al.: Ten-year survival of patients with small-cell lung cancer treated with combination chemotherapy with or without irradiation. J Clin Oncol 8 (3): 396-401, 1990.  [PUBMED Abstract]
4. Lassen U, Osterlind K, Hansen M, et al.: Long-term survival in small-cell lung cancer: posttreatment characteristics in patients surviving 5 to 18+ years--an analysis of 1,714 consecutive patients. J Clin Oncol 13 (5): 1215-20, 1995.  [PUBMED Abstract]
5. Fry WA, Menck HR, Winchester DP: The National Cancer Data Base report on lung cancer. Cancer 77 (9): 1947-55, 1996.  [PUBMED Abstract]
6. Murray N, Coy P, Pater JL, et al.: Importance of timing for thoracic irradiation in the combined modality treatment of limited-stage small-cell lung cancer. The National Cancer Institute of Canada Clinical Trials Group. J Clin Oncol 11 (2): 336-44, 1993.  [PUBMED Abstract]
7. Johnson BE, Bridges JD, Sobczeck M, et al.: Patients with limited-stage small-cell lung cancer treated with concurrent twice-daily chest radiotherapy and etoposide/cisplatin followed by cyclophosphamide, doxorubicin, and vincristine. J Clin Oncol 14 (3): 806-13, 1996.  [PUBMED Abstract]
8. Turrisi AT 3rd, Kim K, Blum R, et al.: Twice-daily compared with once-daily thoracic radiotherapy in limited small-cell lung cancer treated concurrently with cisplatin and etoposide. N Engl J Med 340 (4): 265-71, 1999.  [PUBMED Abstract]
9. Wolf M, Holle R, Hans K, et al.: Analysis of prognostic factors in 766 patients with small cell lung cancer (SCLC): the role of sex as a predictor for survival. Br J Cancer 63 (6): 986-92, 1991.  [PUBMED Abstract]
10. Rawson NS, Peto J: An overview of prognostic factors in small cell lung cancer. A report from the Subcommittee for the Management of Lung Cancer of the United Kingdom Coordinating Committee on Cancer Research. Br J Cancer 61 (4): 597-604, 1990.  [PUBMED Abstract]
11. Chute JP, Venzon DJ, Hankins L, et al.: Outcome of patients with small-cell lung cancer during 20 years of clinical research at the US National Cancer Institute. Mayo Clin Proc 72 (10): 901-12, 1997.  [PUBMED Abstract]

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