Besides the treatment itself, the timing of chemotherapy given to cancer patients can be important to the success of the treatment.
Chemotherapy given after surgery for non-small cell lung cancer (NSCLC) has been shown to increase survival.
A recent analysis of published studies showed that chemotherapy given before surgery for NSCLC also was associated with increased survival and increased time to disease recurrence (return of cancer).
The NSCLC Meta-Analysis Collaborative Group conducted and published this research.
The research team analyzed 15 published studies on the effect of chemotherapy before surgery on survival in patients with non-small cell lung cancer.
Most of the tumors were cancer stage IB to IIIA, and 80 percent of the patients in the studies were men. The studies collected data on the patients for an average of six years.
The results showed a 13 percent increase in survival of NSCLC patients who received chemotherapy before surgery compared to those who did not receive chemotherapy before surgery. This finding meant that 5 percent more patients were alive in five years, or 45 percent of patients were alive instead of 40 percent in five years.
The analysis found that types of medications given for chemotherapy, number of medications given and whether platinum-containing medications or radiation treatment were used did not affect the results.
Age, gender and stage of the cancer also did not affect the survival rates.
Compared to patients who did not receive chemotherapy before surgery, those who were treated with chemotherapy before surgery had a 15 percent lower chance of having a cancer recurrence. These patients had an increase in recurrence-free survival of 6 percent at five years, which raised the chances of recurrence-free survival from 30 to 36 percent.
Those who received chemotherapy before surgery also had a 31 percent lower chance of having tumors found far away from the original lung tumor, compared to patients who did not have chemotherapy before surgery. Preoperative chemotherapy patients had an increase in the chance of distant cancer recurrence-free survival from 60 percent to 70 percent at five years.
The authors noted that chemotherapy before surgery may have benefited patients because it might shrink tumors so that surgery was more likely to remove the entire tumor. These authors also suggested that early chemotherapy might decrease the number of cells that can break from the original tumor and spread to other parts of the body.
Since chemotherapy before or after surgery are both now known to produce benefit to the patients, "Clinicians might consider that preoperative chemotherapy is preferable for poorer prognosis patients with larger, more advanced stage tumors, less able to tolerate chemotherapy after surgery, or in regions where surgery waiting lists are longer," the authors wrote.
"Postoperative chemotherapy might be preferred by surgeons and by patients wishing to have potentially curative treatment immediately, or for those with earlier stage disease," they wrote.
This research was published in the May issue of The Lancet.
Funding for the research was provided by the Medical Research Council UK.
Two of the study collaborators who provided patient data for the study disclosed conflicts of interest. Virginie Westeel disclosed that she received either consultant fees or travel grants from Roche, Lilly, GlaxoSmithKline, AstraZeneca, Chugai, Boehringer Ingleheim, Amgen and Roche. Harry J.M. Groen served as a consultant for Eli Lily, Pfizer and Roche. No other authors disclosed conflicts of interest.