Hello,
I have been ghosting/trolling this site for a few weeks now, having found it through another pipe forum, but havn't registered until now. I think this post warrants finally going through the registration process.
I work in a Level 1 Trauma Hospital (when things go bad at other hospitals, they helicopter that patient to *US*.) I take diagnostic x rays, as well as CAT/CT scans. I'm not a doctor, unfortunately - otherwise, I would have a whole lot more pipes!
Yet, in my line of work, I have had occasion to talk about pipes versus cigarettes with a few doctors. One of them is an ER doctor who smokes like a freight train (cigarettes.) He used to smoke a pipe, but finds it inconvenient, apparently (understandable being an ER physician dealing with random traumas all day, I guess.) When I asked him about the health benefits of pipes versus cigarettes, he told me something like this - "Pipes, without a doubt, are much much MUCH better for you than cigarettes - so long as the smoke is not inhaled into the lungs. I can't really condone smoking in any way, but I can say that pipes - especially in moderation - are BY FAR THE BEST METHOD."
Myself, being somewhat learned in medical things (human anatomy and physiology-wise, almost on par with a physician) - I would say that smoking a pipe, provided the smoke is not inhaled, in moderation (which you state you do), isn't a huge deal. I am of the somewhat-learned opinion that the stress relief involved by smoking a pipe full of your favorite tobacco is doing a whole lot of good for you, in ways that medical tests can't measure in concrete numbers.
I say - enjoy your pipe every now and then. Maybe make it a special event to smoke it once on Sundays. I think the amount of stress relief you gain will far outweigh any dips in chemotherapy effectiveness, which would be extremely minimal anyway - due to the pipe being the method of choice, and the infrequency.
Also, as a side note - I have been privileged enough to work in radiation oncology for a brief time back when was a student. I have witnessed lives saved from cancer by a short duration of exposure to radiation, done in an extremely controlled way that utilizes some recently developed technology (past 3 ish years or so?) designed to expose literally only the area in question (configured 3-dimensionally, often using ultrasound.) The techs literally color code each internal organ, and use lasers to confine the radiation exposure to only the necessary region of interest. It was normal for a patient to show up, get a 5 minute procedure done, and have another 6 months added to their life expectancy this way.
Each type of cancer is different. I don't know if lymphoma is something that can be localized and treated in an isolated way the same way rectal cancer, for instance, can be treat. BUT, it might be something worth bringing up with your physician.
Best of luck to you. And a parting thought - hell, this is YOUR life - you are allowed to make your own decisions about it.