Continuing Hormonal Therapy after Five Years
The data continues to roll in that, at least for some women with ER positive breast cancers, it makes sense to continue hormonal/endocrine therapy for longer than five years. Women have mixed responses to this news, ranging from delight that they will still be taking anti-cancer therapy and feeling somewhat protected to being unhappy at needing to continue a therapy that reminds them of cancer daily and may have some side effects. Most of the studies have focused on tamoxifen, but the evidence is also accumulating about the AIs.
Many ER positive breast cancers are so-called "indolent" cancers (although that always seems like an oxymoron to me) and may recur many years after the first diagnosis. Remaining on hormonal/endocrine treatments for more than five years seems to reduce the risk of death by 10% and of local recurrence by 30%. Those are pretty impressive numbers.
Of course, if you are struggling with side effects from one of these treatments, the numbers need to be balanced against your quality of life. The usual side effects include hot flashes (although they almost always have greatly diminished or disappeared after five years) and joint aches and pains. Personally, I never experienced particularly bad hot flashes, but the stiffness and joint aches surely have persisted; I really dislike hobbling when I first get out of bed in the morning or out of the car after even an hour's drive. However, I loosen up pretty quickly, and the "old lady gait" is definitely preferable to more cancer.
Here is the abstract from a new mega-analysis published in Cancer Research and Treatment and then a link to read more:
Five or more years of adjuvant endocrine therapy in breast cancer: a meta-analysis of published randomised trials
Fausto Petrelli • Andrea Coinu • Mary Cabiddu •
Mara Ghilardi • Veronica Lonati • Sandro Barni
Five years of adjuvant hormonal therapy is the
standard of care in early breast cancer (BC) expressing
oestrogen receptors (ER?). Prolonged duration of adjuvant
endocrine therapy is implemented to prevent recurrence
and death; in particular, its carryover effect may prevent
very late events. This meta-analysis compares the efficacy
of 5 years of hormonal therapy alone with that of additional
years of hormonal therapy, in patients with early BC.
Randomised trials comparing 5 years versus more than
5 years of hormonal therapy in BC were identified by
electronic searches of PubMed, EMBASE, ISI Web of
Science and the Cochrane Central Register of Controlled
Trials. Meta-analysis was performed using the fixed- or
random-effects models. The primary endpoints were
overall survival (OS), BC-specific survival (BCSS) and
relapse-free survival (RFS) reported as odds ratios (ORs)
and 95 % confidence interval (CI). Eight trials, including
29,138 patients, were identified. Overall, in ER? BCs,
extended endocrine therapy beyond 5 years of tamoxifen
significantly improved OS (OR, 0.89; 95 % CI 0.80–0.99;
P = 0.03), BCSS (OR, 0.78; 95 % CI 0.69–0.9;
P = 0.0003) and RFS (OR 0.72; 95 % CI 0.56–0.92;
P = 0.01) compared with 5 years of hormonal therapy
alone. Loco-regional and distant relapses were reduced by
36 and 13 %, respectively. Compared with 5 years of
tamoxifen, additional adjuvant endocrine therapy reduced
risk of death and relapse of ER? BC by *10 and 30 %,
respectively. This strategy should be considered in patients
free of disease after 5 years of hormonal therapy.