Patients who received chemotherapy after surgery to remove colorectal cancer that had spread to their liver or lungs had better long-term outcomes than those who only had surgery, according to an analysis that pooled two similar studies.
Two different clinical trials studied chemotherapy after surgical removal of liver or lung metastases due to colorectal cancer. While neither trial was large enough to draw clear conclusions on its own, researchers combined information from both to decide if chemo made a difference for patients.
After surgery completely removed tumors in lungs or liver, patients were randomly assigned to receive chemotherapy or not. The treatment used was an older one, intravenous 5FU plus leucovorin for five days in a row each month. In both trials it was given for six months.
In all, 278 patients were included in the analysis. Almost all (94 percent) had tumors in their livers.
Overall, chemotherapy helped patients to live longer before their cancer got worse.
- Median progression-free time for those who had only surgery was 18.8 months.
- Progression-free interval for surgery and chemotherapy was 27.9 months.
Patients also lived longer when they had chemotherapy.
- Median survival time for surgery alone was 47.3 months.
- Survival after surgery and chemotherapy was 67.2 months.
After three years, there was little difference in the percentage of patients who were still alive (69.4 percent in the chemo group compared to 71 percent who received surgery alone.) However, after five years, more patients who had chemo were still living (52.8 percent compared to 39.6 percent.)
While the combined numbers did not conclusively demonstrate the value of chemotherapy after surgery to remove metastatic colorectal tumors, they did point in that direction. Writing in the Journal of Clinical Oncology, Emmanuel Mitry and his team said,
This pooled analysis shows a marginal statistical significance in favor of adjuvant chemotherapy with an FU bolus–based regimen after complete resection of colorectal cancer metastases.
They also pointed out that newer chemotherapy regimens might be more effective than bolus 5FU and leucovorin, as they are after chemotherapy for stage II and III colon cancer.
A different study, headed by Bernard Nordlinger, M.D., has shown that chemo given both before and after surgery (perioperative chemotherapy) increases the possibility that patients with resectable liver tumors will be alive and without cancer recurrence three years later. In that trial, 42.4 percent of patients who received perioperative chemo were alive without cancer three years later compared to 33.2 percent who only had surgery.
Still, it is unclear whether chemotherapy before surgery is necessary when liver metastases are surgically resectable or whether it is the chemo after the operation that makes the difference in outcome. Researchers are now working on designing a clinical trial that may help answer that question.
Mitry et al., Journal of Clinical Oncology, Volume 26, Number 30, October 20, 2008.
Nordlinger et al., The Lancet, Volume 371, Number 9617, March 22, 2008.