Treatment Break During Carbo/Taxol - 1264390

Hi Seth,

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."

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"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…

JimC
Forum moderator

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.

-Dr. West