Boogies I sent you an article about the cancer markers that were rising prior to the death of the tumor- it isn't something that there has been much study on that is published- I would encourage you to research Israeli research. They have done some phenomenal research, my problem is that I do not read Hebrew- My partner can trip through it but it was very frustrating because I could find NO translations.
I would consider looking into the juicing aspect for your sister as well - getting as much of the green material into her body as possible right now - you are working with an entire body, not just the breast tissue and cancer markers and by strengthening the whole system you stand a much better chance of seeing some really good results.
Diet is also huge with Breast Cancer - I would encourage you and your sister to look into completely natural foods i fyou have not already - no GMO's or other preservatives- these diets seem to bring dramamtic results when teamed with other forms of treatment.
One last thing that is often overlooked by care providers- your sister needs to be outside as often as possible- I am not sure what happens when we expose ourselves to the outdoors- but it seems to trigger something inside our bodies, more energy, better health. Some are thinking it may be Vitamin D levels- and supplements don't seem to do it.
One last thing that may sound off the wall and useless to you - I work with crystal therapy and Sugilite is specific to cancer- drape her in it, sleep in it, wear it. Selenite also helps counter cancer mutations and Green Calcite will help with psychological end of this.
Disease is never just in the body, Doctors have forgotten that. It starts with our mind and CAN be cured with the mind, however it can be tremendously difficult to work through the types of thoughts and beliefs that have caused a disease while you are battling that disease- I would encourage your sister to find someone who can coach her in a spiritual path of her choosing, shaman - priest-witch-what ever spirtiual path….the understandings that can come from these experiences can be much more powerful than allopathic medicine at times. By working with several methods rather than just one your sister has a much higher chance of recovery.
There is also a list here on the forums that is granny crows list of diseases and treatments- please find that and run through it- thousands of ideas there! Also try this link
Society of Cannabis Clinicians | Quality medical cannabis research and clinician education for cannabis physicians and allied professionals.

I hope this helps, Good Luck, Peace and love to you and your sister! <3