- Series
- Mathematical Biology Seminar
- Time
- Wednesday, April 25, 2012 - 11:05am for 1 hour (actually 50 minutes)
- Location
- Skiles 006
- Speaker
- Leonid Khanin – Idaho State University – khanin@isu.edu
- Organizer
- Leonid Bunimovich
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Over the last several decades, cancer
has become a global pandemic of epic proportions. Unfortunately, treatment
strategies resulting from the traditional approach to cancer have met with only
limited success. This calls for a paradigm shift in our understanding and
treating cancer.
In this talk, we present an entirely
mechanistic, comprehensive mathematical model of cancer progression in an
individual patient accounting for primary tumor growth, shedding of metastases,
their dormancy and growth at secondary sites. Parameters of the model were
estimated from the age and volume of the primary tumor at diagnosis and volumes
of detectable bone metastases collected from one breast cancer and 12 prostate
cancer patients. This allowed us to estimate, for each patient, the age at
cancer onset and inception of all detected metastasis, the expected metastasis
latency time and the rates of growth of the primary tumor and metastases before
and after the start of treatment. We found that for all patients: (1) inception
of the first metastasis
occurred very early when the primary tumor was undetectable; (2) inception of
all or most of the surveyed metastases occurred before the start of treatment;
(3) the rate of metastasis shedding was essentially constant in time regardless
of the size of the primary tumor, and so it was only
marginally affected by treatment; and most importantly, (4) surgery, chemotherapy and possibly radiation bring about a dramatic
increase in the rate of growth of metastases. Although these findings go
against the conventional paradigm of cancer, they confirm several hypotheses
that were debated by oncologists for many decades. Some of the phenomena
supported by our conclusions, such as the existence of dormant cancer cells and
surgery-induced acceleration of metastatic growth, were first observed in
clinical investigations and animal experiments more than a century ago and
later confirmed in numerous modern studies.