  The goal of immunotherapy is to enhance the ability of the immune system to
kill cancer cells. Immunotherapy is more effective and, in general, the
prognosis is better, when more immune cells infiltrate the tumor. We explore
the question of whether the spatial distribution rather than just the density
of immune cells in the tumor is important in forecasting whether cancer recurs.
After reviewing previous work on this issue, we introduce a novel application
of maximum entropy to quantify the spatial distribution of discrete point-like
objects. We apply our approach to B and T cells in images of tumor tissue taken
from triple negative breast cancer (TBNC) patients. We find that there is a
distinct difference in the spatial distribution of immune cells between good
clinical outcome (no recurrence of cancer within at least 5 years of diagnosis)
and poor clinical outcome (recurrence within 3 years of diagnosis). Our results
highlight the importance of spatial distribution of immune cells within tumors
with regard to clinical outcome, and raise new questions on their role in
cancer recurrence.
