Efficacy of Carbo/Alimta - 1263645

healmymom
Posts:44

With regard to the efficacy Carbo/Alimta -- I have some questions. It's my understanding that it has apprx. 40% chance it will work. I've reviewed lots of people's cases on this website, and realize that most of the time, "working" means 50% shrinkage, or 65% shrinkage, and my mom's dr. said that even if it has just stayed the same, it is considered working.
But with regard to the technically 60% chance of not working, does that mean that in some people the chemo has no effect whatsoever, that the cancer just keeps growing as it the chemo hadn't even been administered?

I don't recall seeing tooo many people's write-ups who said it did absolutely nothing

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Reply # - May 7, 2014, 01:37 PM

JimC
Posts: 2753

Hi healmymom,

I think the confusion here is based on how clinical trials define "response" to treatment. Most trials define response as either complete disappearance of the tumor being measured, or partial response, which requires that the tumor is reduced in size by a specified percentage, often 50%. So if you've heard a statistic that says Carbo/Alimta only "works" 40% of the time, that is likely what is meant - the response rate, as the term is strictly defined for trial purposes, was 40% in a particular trial or series of trials.

But that's only a small part of the story. Many other patients gain a benefit from Carbo/Alimta, including tumor shrinkage less than 50% or stable disease. Either of those possibilities is a good outcome, and although it is generally better to have a complete or partial response, there are patients who never meet those criteria but achieve stable disease for extended periods of time, which is better than having a response but a quick recurrence.

It is true that some patients progress right through a particular treatment regimen, but the percentage is not 60% as might be implied from the statistics you saw.

Dr. West discusses stable disease here: http://cancergrace.org/cancer-101/2007/01/13/stable-disease-and-clinica…

JimC
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Reply # - May 7, 2014, 09:30 PM

Dr West
Posts: 4735

When I provide estimates for what patients might expect from first line chemo for advanced NSCLC, I generally say that the response rate for significant tumor shrinkage is in the 30-35% range (40% is a tad on the high side), with another 40-45% demonstrating stable disease or perhaps mild shrinkage. Because the cancer would almost always grow as a default plan, this combined 70-75% "disease control rate" that includes those patients with stable disease or significant tumor shrinkage likely represents the proportion of patients who benefit at least a little, if not a lot, from chemotherapy.

Beyond that, there are perhaps 25-30% whose cancer progresses through chemo, and they likely benefit little or not at all. There may be a small subset of those patients who have the cancer progress more slowly on chemo than they would off of it (perhaps damning with faint praise), but we'd obviously hope for better results than that, and there are a minority of patients who experience net harm by experiencing significant side effects from chemo but having the cancer grow right through it. Fortunately, that's really a small proportion.

In the end, like just about everything in medicine, it's a question of probabilities. Is there a chance that chemotherapy could lead to no benefit or even net harm? Yes, but it's quite a bit more likely to help patients than to harm them, and the probability of benefit from first line chemotherapy is the most favorable benefit vs. risk proposition of any option for patients who don't have a "driver mutation" like an EGFR mutation or ALK rearrangement.

Good luck.

-Dr. West

Reply # - May 15, 2014, 09:45 AM

healmymom
Posts: 44

thank you for your responses -- they are always helpful.

My mom had her CT scan this week, we will get results next Wed. at dr. appt.
I am EXTREMELY worried because:
-- this week her mom's breathing when she walks just a little seems to have gotten worse
-- the initial lump at her lung operation incision site (on her left side rib) might have shrunk a tiny bit, but now there appears a much bigger lump a little lower and next to it and a it's hard all along the rib right below where the lump was. It's very painful to her

I am worried that the cancer is progressing around the pleural and making it rigid, thus causing her breathing to get worse, and that is has spread along her left rib.

Is there any other explanation besides what I'm thinking that would acct. for these things.

Reply # - May 15, 2014, 01:29 PM

carrigallen
Posts: 194

One idea is to consider a few doses of palliative radiation, if a patient is having severe pain due to rib or chest wall invasion by a tumor. This step can often help alleviate pain. This type of radiation can often be accomplished over 5 or so daily treatments.This can usually be set up by an outside referral through your medical oncologist.

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