From the Desk of Dr. Lenz
MSI in Stage II Colon Cancer: Chemotherapy or Not?
Some of the most interesting data presented at ASCO was the data on MSI and 18qLOH in a European clinical trial.
Last year at ASCO, Dr. Daniel Sargent presented new data that patients with stage II disease with microsatellite instability do not only not benefit from 5-FU, but they may be harmed, and it was recommended to test for MSI in all stage II colon cancer patients and in the presence of MSI-high not to give 5-FU. For stage III colon cancer that was not the case.
This year, the PETACC-3 clinical trial was analyzed for MSI and did not show the same the same findings. It seems that chemotherapy does not harm these patients, and they may benefit.
This has been an ongoing controversy over the last couple of years with some studies showing benefit and other not. Last year’s ASCO showed there even may be harm. What MSI means is now again up in the air. We can certainly state that the presence of MSI is a GOOD prognostic marker, meaning that these patients have a lower risk of tumor recurrence. However, if chemotherapy is beneficial or not is still not clearly answered.
Another finding in this clinical trial showed that 18q deletions are not prognostic in stage II disease when MSI status is known. That is important because our clinical trial E-5202 in the US assumed that patients with an 18q deletion are at higher risk for tumor recurrence independent of MSI, which may alter the interpretation of the clinical trial.
All these data show that we are learning a tremendous amount about the molecular make up of tumors, but it also shows that it is not easy to develop clinically meaningful markers. However, there is no doubt that new markers will be identified and validated over the years to come and will make our personalized oncology care a reality.
This news article was originally posted on June 8th, 2009 and was accurate at the time of publication. Since then, information may have changed or links may now be outdated. Please call our Answer Line 1-877-427-2111 for the latest information, or talk to your doctor before making any medical decisions.
Posted by Heinz-Josef Lenz, MD on June 8th, 2009
Tags: 18qLOH, ASCO 2009, MSI, personalized medicine, Understanding Genetics
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Sue
June 16, 2009 at 2:59pm
I am on my last trtment with folfox 4 without Avastin thru the E5202 trial.
My markers were: Mss with 18q LOH deletion. I would like to know what percentage of survival at 5 yrs. that puts me at. Noone will tell me.
I know this is just statistical, but still would like to know.
Heinz-Josef Lenz
June 16, 2009 at 7:53pm
that is great news that you received FOLFOX since wiht MSS you have an increased risk for recurrence and have benefit from 5-FU. there is no question about the 18q deletion. According to the publication of Watanabe with MSS and 18q you have a similar risk like stage III cancer which is always treated wiht FOLFOX. HJL
Sue
July 10, 2009 at 11:11am
Hello again Dr. Lenz,
I finished my trtment with Folfox IV 3 wks ago. I am to get a CT scan and asked for a PET scan also. My Dr. ordered just a PET scan. Shouldn’t I receive both?? I had Stage II MSS/18q LOH deletion, surg. removed mod. diff, adeno, T3, N0, MX
Sue
Heinz-Josef Lenz
July 10, 2009 at 5:19pm
usually would do a CT or combined CT/PET not PEt alone since small lesions are not picked up by pet they need to be larger than 5mm but these can be seen on CT. HJL
anon
May 5, 2010 at 2:35am
I am a doctor and my father ,66 years old, had rectal tm and had an operation last week. Tm was 10 cm away from tha anal verge, CEA level was normal. Tm size was 2x5x3 cm (0.8 cm depth), subserosal invelvement was detected . Lymph Node was negative. Thus, tumor stage is 2a,T3N0M0. and MSI findings were present in the specimen. 18 q deletion is not known at the moment. What kind of treatment and further evaluations would you recommend for my dad? Chemo?Chemo+radiatherapy?
Jodi
June 15, 2010 at 11:20pm
Hiello Dr. lenz. i’ve never posted here and hop I’m doing this correctly.
My mom has stage II Colon cancer no lymphnodes, T3NOMO, MSS and 18Q markers with poorly differentiated cells, High grade tumor.
Does Xelox, Folfox work best for this high risk type? Or is there another recomended chemo more effective for this. I know there is a study with Avastin. Is the 18Q marker high enough risk to use Avastin? Confused and running out of time to make the choice for type of chemo. I thought I’d ask for your input or explinations of chemo for this 18q MSS group? Thank you so much in advance for any input or help you can offer!
Jodi