Ibrance and Letrozole: Newly Diagnosed Treatment

I have been taking Ibrance and Lextrozole for a year. I had scans read three days ago by my oncologist. Hallelujah… my MBC is in remission. My breast tumor is gone, only scar tissue. Spine lesions gone. OMG!!
This is my second bout with Cancer, in 2018 I had Uterine Cancer. I had chemo and radiation and surgery to remove the tumor. To this day NED. These drugs have been kicking Cancer’s ass.

The following was in today's ASCO Post.
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PALOMA-2: No Overall Survival Benefit Reported With Palbociclib/Letrozole in Advanced Breast Cancer

"The final overall survival analysis of the phase III PALOMA-2 trial has shown no significant benefit for palbociclib given with letrozole, vs letrozole and placebo, as a first-line treatment in hormone receptor–positive, HER2-negative metastatic breast cancer."

The results were reported at the 2022 ASCO Annual Meeting by Richard Finn, MD, Professor of Medicine at the David Geffen School of Medicine, University of California, Los Angeles."
https://ascopost.com/news/july-2022/no-overall-survival-benefit-reported-with-palbociclibletrozole-in-advanced-breast-cancer/?utm_source=TAP%2DEN%2D072622&utm_medium=email&utm_term=4cf962011c9ee11a42cbb2ed9ce1807f

Please note that the study did note the effectiveness of letrozole. It just didn't find better results by adding palbociclib.

@callalloo the conclusions of this study were more complicated, mainly because of missing date that affected results. All in all the article you linked favors the use of both drugs, Femara and Ibrance (brand names). I urge people to read the entire article and not just the headline, which is misleading. I am posting excerpts and hope people will read them.

"To demonstrate the impact of missing data, Dr. Finn showed a post hoc analysis excluding patients for whom survival data were not available. In that analysis, the median overall survival was 51.6 months with palbociclib/letrozole vs 44.6 months with letrozole alone (HR = 0.869; 95% CI = 0.706–1.069)."

"The time to chemotherapy was 38.1 months with palbociclib/letrozole vs 29.8 months with letrozole alone (HR = 0.730; 95% CI = 0.607–0.879)."

"Regarding other outcomes that affected quality of life, Dr. Finn reported the median duration of treatment and the time to chemotherapy were prolonged with palbociclib plus letrozole. The median treatment duration was 22.0 months vs 13.8 months, and at each benchmark, more of the palbociclib arm were still on treatment. “At 6 years or longer, this was three times as many (16% vs 5%),” he noted."

" For the largest subgroup of patients—those with a disease-free interval of more than 12 months—overall survival increased from 44.6 months in the control arm to 64.0 months with palbociclib/letrozole"

I have been taking Ibrance and Lextrozole for a year. I had scans read three days ago by my oncologist. Hallelujah… my MBC is in remission. My breast tumor is gone, only scar tissue. Spine lesions gone. OMG!!
This is my second bout with Cancer, in 2018 I had Uterine Cancer. I had chemo and radiation and surgery to remove the tumor. To this day NED. These drugs have been kicking Cancer’s ass.

I included the link so that people can read the whole article and am glad that you did. In a few places the author noted where the results of both drugs v. letrozole and a placebo or letrozole alone "were not statistically significant." I assume that it is that, that points to a lack of clear benefit that led to the headline conclusion.

The authors cited the problem of missing data as you noted. But statistically-valid conclusions cannot be drawn by ignoring missing data in such a study. That would be cherry-picking data or biased outcome.

So they mentioned what they could deduce (which you excerpted) from the incomplete data but nonerheless concluded as stated in the headline. At least that's what I deduce from the seeming discrepancies.

It would be valuable to know the cause of the missing data. E.g., if people dropped out if the study and why. And why it was the missing data was "disproportionate"? One reason people drop our of studies is adverse effects. In such a case, had the people stayed in the study, several of the measure variables would have been negatively affected.

But here's one conclusion from the study and the link again for anyone interested.
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“Overall survival was numerically longer in the palbociclib-plus-letrozole arm, but the results were not statistically significant,” Dr. Finn announced. “The interpretation of overall survival is limited by the large and disproportionate percentage of patients with missing survival data [ie, lost to follow-up or censored] between the treatment arms.”
https://ascopost.com/news/july-2022/no-overall-survival-benefit-reported-with-palbociclibletrozole-in-advanced-breast-cancer/?utm_source=TAP%2DEN%2D072622&utm_medium=email&utm_term=4cf962011c9ee11a42cbb2ed9ce1807f

@callalloo I erred in not providing that excerpt as well. It supports the headline's conclusion, and I was trying to show the other results. But the quotation you provide is also important so apologies for failing to include that excerpt.
I find the study results very confusing. It seems that the missing data had a significant impact on results. Personally, I would still take Ibrance until a better study (or my doctor) told me not to!

Will you continue with either drug during remission? Or can you monitor with scans and no drugs?