Hi Jessica.
There are, many, many different types of breast cancer.
Each has it's own profile of hormonal response, stage, grade, involvement of lymph nodes, specific breast tissue that it affects (eg ductal etc), genetic risk factors and places they are likely to spread to.
Your oncologist can give you very specific statistical information on the likely spread of your particular cancer to specific body parts including the scalp and fingers. It's not a "one size fits all" scenario.
A review of studies into the safety of cold caps said this;
"The 2010 expert opinion review paper by Rugo reviewed the existing studies on scalp metastases. They concluded that, “Scalp cooling has not been shown to increase the incidence of scalp metastases in patients with both early and late stage breast cancer….It is our expert opinion that scalp cooling can and should be offered to breast cancer patients who will be treated with adjuvant chemotherapy, and also those who are offered palliative chemotherapy associated with a significant risk of alopecia. The risks involved appear to be extremely small and the potential gain for the large number of women receiving adjuvant chemotherapy for breast cancer in the United States is substantial” (Rugo, 2010)."
For more info see the full document here
http://www.rapunzelproject.org/LinkClick.aspx?fileticket=6zLSpIu5Hro%3d&tabid=58
In Australia the cold caps aren't very well known (they have been used for nearly 20 years in Europe) so some oncologists here automatically discount them because they are unfamiliar.
All the best,
Sharon