Lung Cancer.pdf

190 R. Komaki
lished between 1979 and 1987 that investigated chemotherapy with and
without TRT in patients with limited-stage SCLC. The authors reported an
increase in 2-year survival rates from a range of 10% to 15% to a range of
25% to 30%. Most, if not all, of the improvement in outcome was attributed
to more effective combination chemotherapy regimens.
Today, chemotherapy regimens commonly used to treat patients with
limited-stage SCLC include etoposide, cisplatin, and paclitaxel and carboplatin
and irinotecan. Paclitaxel, cisplatin, and etoposide plus concurrent
radiation therapy (Ettinger et al, 2000) and ifosfamide, cisplatin, and
etoposide plus concurrent radiation therapy (Glisson et al, 2000) have not
been shown to have long-term benefits compared to treatment with cisplatin,
etoposide, and concurrent radiation therapy for patients with limited-stage
SCLC. Irinotecan has been reported to be more effective than
etoposide and cisplatin for extensive-stage SCLC (Noda et al, 2002).
Chemotherapy for SCLC is discussed in more detail in chapter 11.
Chemotherapy and Thoracic Radiation Therapy in Combination
Although early development of distant metastases is a critical problem in
patients with SCLC, making chemotherapy an important element in the
treatment regimen, intrathoracic failure becomes more important once
distant metastasis is controlled. Two meta-analyses, using different methods,
confirmed the value of adding TRT to chemotherapy in decreasing
the rate of local recurrence and improving survival in patients with SCLC.
Warde and Payne (1992) analyzed results from 11 prospective randomized
trials of chemotherapy with or without TRT for patients with limitedstage
disease and found an absolute increase in overall survival at 2 years
from 15% to 20.4% and an absolute increase in local control at 2 years from
15% to 40% with the addition of TRT. Pignon and colleagues (1992) collected
data on 2,140 patients from 16 randomized trials comparing
chemotherapy alone versus chemotherapy plus TRT and found an improvement
in absolute survival of 5.4% at 3 years.
Concurrent Chemotherapy and Thoracic Radiation Therapy
The very poor survival outcomes even in patients treated with combination
therapy indicated that the effectiveness of both TRT and systemic
chemotherapy needed to be improved. One idea for improving local and
distant control in patients with SCLC was to deliver chemotherapy concurrently
with radiation therapy so that chemotherapy would work as a
radiosensitizer. The potential advantages of concurrent chemotherapy
and radiation therapy are early use of both modalities, to provide synergistic
effects; the ability to plan radiation therapy more accurately since
there is no induction chemotherapy, which can obscure the original tumor
volume; and short overall treatment time (high dose intensity), which prevents
proliferation of clonogens. The disadvantages are enhanced normal
tissue toxicity, which could necessitate dose modification or treatment