Several studies presented at ASCO looked a biomarkers that might predict cancer recurrence or patient survival in stage II and III colon cancer and whether patients could be chosen to receive chemotherapy based on those markers.  Of special interest was the hypothesis offered by two researchers from the PETACC-3 clinical trial that stage II and stage III may be very different biologically.  As Dr. Arnaud Roth said, “. . .in other words, could be different diseases.” Read the rest of this entry »

The first genomic test to predict whether or not stage II colon cancer will recur has been developed and validated in a large number of tumor tissue samples from patients in the United States and the United Kingdom.  The 12 gene assay can reliably predict whether an individual patient has a low, intermediate, or high risk of having their cancer return.

Doctors and patients will be able to use the Recurrence Score, along with other clinical indicators, to decide whether further chemotherapy treatment after surgery should be considered or whether they can safely skip chemo and its risks.

However, the study was not able to link recurrence scores with benefits from 5-FU and leucovorin chemotherapy. Read the rest of this entry »

Since the last ASCO meeting in June 2008 not only has KRAS made headlines but also microsatellite instability (MSI).

Microsatellite instability has developed into the most important prognostic and predictive marker for patients with stage II colon cancer. Recent studies presented by Dr. Daniel Sargent at ASCO showed that patients with stage II colon cancer who have microsatellite instability did not benefit from 5-FU chemotherapy. Therefore these patients with no risk factors such as clinical obstruction, lymphovascular invasion, poorly differentiated adenocarcinoma, or insufficient lymph node collection should not receive 5-FU. Read the rest of this entry »

Advance Abstracts from ASCO 2008

How far a colon or rectal cancer penetrates through the wall of the bowel may be more important in deciding survival risks than current staging that focuses on positive lymph nodes.

Five year survival statistics for a large number of rectal and cancer patients verified an earlier study that found some stage III colorectal cancers had better prognosis than stage II cancers that extended through the bowel wall but did not invade nearby lymph nodes.

The information has implications for treating colorectal cancer after surgery.

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