Chemotherapy in advanced nonsmall cell lung cancer: indication, intensity, and duration

Duration of Chemotherapy for Advanced Non–Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis of Randomized Trials

Purpose

To determine if it is preferable to extend chemotherapy beyond a standard number of cycles in patients receiving first-line chemotherapy for advanced non–small-cell lung cancer.

Methods

We searched biomedical literature databases and conference proceedings for randomized controlled trials (RCTs) comparing a defined number of cycles with continuation of the same chemotherapy until disease progression, a larger defined number of cycles of identical chemotherapy, and a defined number of cycles of identical initial chemotherapy followed by additional cycles of an alternative chemotherapy. Meta-analysis was performed using the fixed effect model. The primary outcome was overall survival (OS); secondary outcomes included progression-free survival (PFS), adverse events (AE), and health-related quality of life (HRQL).

Results

We found 13 RCTs including 3,027 patients. Extending chemotherapy improved PFS substantially (hazard ratio [HR], 0.75; 95% CI, 0.69 to 0.81; P < .00001) and OS modestly (HR, 0.92; 95% CI, 0.86 to 0.99; P = .03). Subgroup analysis revealed that effects on PFS were greater for trials extending chemotherapy with third-generation regimens rather than older regimens (HR, 0.70 interaction v 0.92 interaction; P = .003). Extending chemotherapy was associated with more frequent AE in all trials where it was reported and impaired HRQL in two of seven trials.

Conclusion

Extending chemotherapy, particularly with a third-generation regimen, improved PFS substantially, but OS less so. Future trials should test extending treatment with more effective and/or better-tolerated agents.

Lung cancer after treatment for Hodgkin's lymphoma: a systematic review

Developments in modern chemotherapy and radiotherapy mean that most patients with Hodgkin's lymphoma can now be cured. However, the long-term effects of anticancer treatment include an increased risk of a second malignant disease. We have done a systematic review of studies reporting long-term complications of the treatment of Hodgkin's lymphoma published in English since 1985. These studies show that risk of lung cancer is significantly increased in patients treated for Hodgkin's lymphoma, with a reported mean relative risk of 2.6-7.0 and a significantly increased absolute excess risk. The absolute excess risk increases with time from treatment, for as long as 20-25 years, and is highest in patients treated at age 45 years or older. Both chemotherapy and radiotherapy contribute to the risk, and evidence suggests that the effects are additive. Cigarette smoking seems to multiply the risk associated with both chemotherapy and radiotherapy. In the high-risk group of patients, 50-150 patients per 1000 are expected to develop lung cancer by 10-20 years after treatment. The role of screening in this group of patients has not yet been assessed, but an international study combining CT with genomic and proteomic assessment is planned.

Chemotherapy Dose Density in Early-Stage Breast Cancer and Non-Hodgkin’s Lymphoma

Delivering standard-dose chemotherapy on schedule is important for survival in early-stage breast cancer and non-Hodgkin's lymphoma. Trials of dose-escalated regimens, in which higher-than-standard doses of chemotherapy are used, have produced equivocal results. In contrast, dose-dense regimens, in which standard doses are given with shorter (usually 14-day) intervals between cycles, have been more efficacious than standard 21-day regimens in trials in both early-stage breast cancer and non-Hodgkin's lymphoma. Furthermore, a shorter course of chemotherapy is likely to cause less disruption in patients' lives. Despite the evidence of the importance of maintaining chemotherapy dose intensity (the amount of drug administered/unit of time), undertreatment of patients with early-stage breast cancer and non-Hodgkin's lymphoma is common. Neutropenia is the primary dose-limiting toxicity of many chemotherapy regimens, and it is frequently managed by dose reductions and delays that decrease dose intensity. Colony-stimulating factors reduce the prevalence and severity of neutropenia and its complications, and their proactive use can improve adherence to the planned schedule of both standard-dose and dose-dense chemotherapy The promising results with dose-dense chemotherapy in early-stage breast cancer and non-Hodgkin's lymphoma indicate that it should be tested in patients with other chemosensitive tumors.

Pharmacogenomic strategies for developing customized chemotherapy in non-small cell lung cancer

In this review, we deal with six groups of cytotoxic drugs commonly used in the treatment of non-small cell lung cancer (NSCLC). Although there are many reviews of thymidylate synthase (TS) and antifolate inhibitors, in this article, we have tried to highlight aspects that are more important for medical oncologists to consider when treating NSCLC patients. There is compelling evidence that TS gene transcripts and TS polymorphisms could be used to decide which patients can best benefit from adjuvant chemotherapy approaches, especially in colorectal cancer, and not less importantly, to tailor chemotherapy in metastatic NSCLC when using drugs akin to fluorouracil, such as pemetrexed. Secondly, cisplatin is central to chemotherapy combinations and evidence indicates that DNA repair capacity influences response to cisplatin-based regimens. ERCC1 gene transcript stands out as a predictive marker of cisplatin sensitivity. Thirdly, preliminary studies indicate that upregulation of beta-tubulin III correlates with response to paclitaxel and vinorelbine. Fourthly, overexpression of ribonucleotide reductase can influence response to gemcitabine. Fifthly, we describe mechanisms of resistance to topoisomerase I inhibitors, although this subject has not yet been completely elucidated. Finally, to understand the mechanisms of resistance to EGF-R inhibitors, which have been shown to be useful in many different types of cancer, the Src-STAT signaling pathways are described here in detail. Hopefully, the assessment of Src and of STAT-3 can be implemented as predictive markers.