Indeed, there appears on average to only be a survival benefit from adjuvant chemo in a small number of Stage II patients; the challenge is in identifying which patients are most likely to benefit, given the risks and costs of doing chemotherapy.
The NCCN guidelines suggest you might consider no chemo or a ‘lighter’ chemo (ie just Xeloda / capecitabine) for a ‘low risk’ stage II. For a ‘high risk’ stage II, treatment with FOLFOX may be indicated.
The ‘high risk’ factors identified are:
- Close or positive surgical margins
- Grade 3 or 4 cancer cells
- Lymphatic or vascular invasion
- Perineural invasion
- Fewer than 12 lymph nodes sampled
- Bowel obstruction or perforation
From your post, it seems you have 2 of these risk factors (EMVI and PNI), suggesting adjuvant FOLFOX may be appropriate.
There is an odd paradox where sometimes Stage II outcomes seem to be worse than Stage III; potentially because Stage II is not treated as aggressively. If I were in your shoes I would be giving serious thought to doing the adjuvant chemo. This may also depend on your age and overall health status. There also are things you can do minimise the long-term risks - for example I believe there are recent recommendations that 6 cycles of FOLFOX is sufficient for Stage II adjuvant treatment, which significantly reduces the risk of permanent neuropathy (vs 12 cycles).
As others have said too, your MSI status should be a consideration in this, along with any other mutations (RAS/BRAF).
If you’d like to be really cutting edge, you might inquire about ctDNA testing after surgery. There is recent research showing this can be a strong predictor of residual recurrence risk after curative surgery. You might have to pay for this yourself but it could be a game-changer in terms of insight:https://jamanetwork.com/journals/jamaon ... le/2733132
Not an easy call, but best of luck.