hCG has definite implications for women with a history of breast cancer. It is important to know what type of cancer, and how aggressive the treatment and the amount of time in remission to have a complete risk and benefit overview.
The hCG as a side effect can stimulate the ovaries to increase progesterone primarily and estrogen secondarily. This is responsible for some of the minor hormonal side effects which can be seen while on the diet and don’t generally cause significant issues outside of a few specific preexisting gynecological health conditions.
However, for breast cancer which is estrogen receptor positive, or progesterone receptor positive the hCG’s effect of increasing these hormones can actually stimulate or accelerate the existing cancer condition. If a patient is a breast cancer survivor, there may still be some cancerous cells which are undetected and the stimulation could cause them to grow.
For any existing hormone receptor positive breast cancer hCG is absolutely contraindicated. In breast cancer which is hormone receptor negative, meaning it does not grow or respond to any hormone changes, the hCG and the hormone shift it causes should not cause any interaction or problems.
For any undiagnosed breast mass, or suspicious breast lesion the hCG should not be used until a full diagnostic workup has been completed and the cause found to be non HR positive in nature. Additionally if patients have not had appropriate age and risk based breast exams or mammograms within standard screening time frames, then it is not possible to know the risk and the program would not be recommended.
Some situations can arise which make the risk assessment more complicated such as a complete oophorectomy (ovaries removed) , a bilateral mastectomy (breast tissue removed) or both. Some breast cancer survivors who have had very aggressive and prophylactic treatment may not have ovaries which which are what cause the increase hormones, or may have had all their breast tissue removed which should theoretically eliminate the risk by virtue of removing the tissue which could cause problems. These rare exceptions and situations are very individual and often require co-council with the patients existing oncologist and primary care providers to fully determine the risk.
As a general rule, because there are a lot of ways to lose weight which do not involve hCG and because hCG can increase hormones and therefore present some risk a very conservative approach is taken. The risk of triggering a cancer relapse dramatically outweigh the benefit of losing weight at a fast rate on hCG. The risk of being overweight itself is also going to be less than the risk of stimulating cancer cells and triggering a relapse.
Out of all the weight loss programs that exist, the hCG may be one of the few which actually can interact with specifically hormone sensitive breast cancer, and so given the vast array of choices and the extreme nature of the risk, hCG should not be recommended for hormone receptor positive breast cancer survivors. This is with keeping the best interest of HR positive cancer survivors in mind.
As a side note while on the topic of hCG and its effect on breast health, its worth mentioning that benign fibrocystic breast tissue, or dense breast tissue (all of which are very common) can also sometimes be hormone sensitive (typically to estrogen). Some patients who are sensitive to the hormone changes can experience mild breast tenderness while on hCG which is not related to any cancer risk. hCG does not cause cancer, only as discussed here, can aggravate or accelerate specific kinds of cancer.