RT -
There is a four-fold increased risk of non-Hodgkins lymphoma among patients with celiac disease (gluten sensitivity). Based on that, I would recommend ANY lymphoma patient go on a completely gluten-free diet. I see lots of patients who don't have full-fledged celiac disease but are sensitive to gluten to some degree - if it would help your body be less hospitable to this cancer, why not? After all, we humans didn't eat wheat before 10,000 years ago anyway.

Here's an abstract from the medical literature:
Cancer Causes Control. 2011 Oct;22(10):1435-44. Epub 2011 Jul 14.
Non-Hodgkin lymphoma and gluten-sensitive enteropathy: estimate of risk using meta-analyses.
Kane EV, Newton R, Roman E.
Source

Epidemiology and Genetics Unit, Department of Health Sciences, University of York, Seebohm Rowntree Building, Heslington, York, YO10 5DD, UK. eleanor.kane@egu.york.ac.uk
Abstract
OBJECTIVES:

Gluten-sensitive enteropathy, including coeliac disease and dermatitis herpetiformis, is associated with non-Hodgkin lymphoma (NHL), and particularly enteropathy-associated T-cell lymphoma (EATCL). We conducted a meta-analysis to quantify the association.
METHODS:

Fifty-four risk estimates (range 0.28-300) were pooled using random-effects meta-analysis. Potential sources of variation were examined using sensitivity analyses and meta-regression.
RESULTS:

Thirty-one estimates with gluten-sensitive enteropathy diagnosed by serology then biopsy, serology alone, or recorded in medical notes accounted for half the variation in risks, giving a pooled estimate of 4.42 (95% confidence interval (CI) 3.72-5.26, I2 = 0%). Men and women had similar pooled risks. Risks were largest when these conditions were diagnosed using biopsy and lowest when self-reported. Study design, comparison population, geography or gluten-sensitive enteropathy type explained less of the variation. EATCL estimates ranged from 6 to 200; an association with diffuse large B-cell lymphoma (DLBCL) was also observed (pooled risk estimate = 1.97, 95% CI 1.23-3.15).
CONCLUSIONS:

Where gluten-sensitive enteropathy was diagnosed using modern techniques, NHL risk was increased fourfold. At this level, one in 2,000 persons with gluten-sensitive enteropathy develops NHL each year. In addition to EATCL, DLBCL and possibly other subtypes may be linked to these conditions, and these weaker associations could be investigated in large population-based cohorts with biological samples.