My dad completed his fourth cycle of carbo/taxol almost 3 weeks ago. At his next appointment this Tuesday, the plan is to decide if he is up for continuing with cycles 5 and 6. My dad's cough is completely gone, and he is having no pain from his mets. However, he has been really tired throughout treatment and it seems as though cycles 3 and 4 have hit him the hardest. His oncologist blamed the increasing fatigue on the treatment and not the cancer, based on my dad's favorable scan results. I know the question of 4 vs 6 cycles of chem has been discussed repeatedly here, but I'm wondering whether if it ever makes sense to take a treatment break after cycle 4 and then resume at some point in the future with cycles 5 and 6 and then hopefully move on to maintenance therapy, so as to delay use of maintenance drugs (and the cancer's resistance to them) for as long as possible.
Fri, 06/13/2014 - 14:20
No one really knows how acquired resistance develops, so delaying the use of a particular treatment, taking lower doses of it or lengthening the interval between administrations of the drug are all just guesswork. In addition, the greatest benefit from a platinum doublet such as carbo/taxol occurs in the first two cycles, then a lesser benefit in cycles 3 and 4. By cycles 5 and 6, the likelihood of a significant marginal benefit is fairly small, and the risk of a hypersensitivity reaction to carbo increases, while bone marrow function continues to decrease. Since bone marrow function doesn't tend to bounce back quickly, taking a break before cycles 5 and 6 probably does little to help toxicity issues.
As Dr. West has written:
"...prolonged chemotherapy can increase cumulative side effects, and there was no evidence that prolonged treatment improved survival. This became especially important in the last few years, now that we have therapies with a proven survival benefit as second-line therapy or later. Patients are living longer and have an increasing number of options for treatment after first-line, so we want to ensure that patients have the best balance of effective treatment and good quality of life as possible, and that they are candidates for later therapies while still having strength and good organ function (liver, kidney, and also bone marrow function with good blood counts). It is therefore increasingly important to determine when we’ve reached a point of diminishing returns and should stop a treatment."
[continued in the next post]
Fri, 06/13/2014 - 14:21
[continued from the previous post]
"In fact, these trials and others have shown that it’s very unlikely to have ongoing tumor shrinkage beyond four cycles, and beyond the point of 3-4 cycles, tolerability of treatment also becomes an increasingly important factor. Moreover, with additional therapies that are likely to provide some clinical benefit available in the second-line setting and potentially beyond that, I strongly suspect that the benefits for prolonged first-line therapy are even more diluted by the growing number of effective options that will follow." - http://cancergrace.org/lung/2007/01/17/duration-of-chemo-in-advanced-lu…
Fri, 06/13/2014 - 20:05
There are certainly a lot of grey areas in terms of what to do at this time, but I don't think there would be much incremental benefit vs. incremental toxicity for 2 additional cycles. That said, there's really no evidence to favor or disfavor any of these ideas over any other.
I wish it were possible to say more, but this is really just a clinical setting in which judgment plays a big part, along with patient preference.
Sat, 06/14/2014 - 09:48
Thank you Jim and Dr. West.
Dr. West: Your description of this situation as a grey area is actually very reassuring -- since there is no evidence either way, I feel like any decision we do make won't be the "wrong" decision, and since I have the utmost of confidence in his doctors, we have no hesitation to rely on their judgment in this situation.