I am pleased to report that our paper has now been accepted. You can download the accepted preprint here. We also have a lot of supplementary material, including simulation movies, simulation datasets (for 0, 15, 30, adn 45 days of growth), and open source C++ code for postprocessing and visualization.
I discussed the results in detail here, but here’s the short version:
- We use a mechanistic, agent-based model of individual cancer cells growing in a duct. Cells are moved by adhesive and repulsive forces exchanged with other cells and the basement membrane. Cell phenotype is controlled by stochastic processes.
- We constrained all parameter expected to be relatively independent of patients by a careful analysis of the experimental biological and clinical literature.
- We developed the very first patient-specific calibration method, using clinically-accessible pathology. This is a key point in future patient-tailored predictions and surgical/therapeutic planning.
- The model made numerous quantitative predictions, such as:
- The tumor grows at a constant rate, between 7 to 10 mm/year. This is right in the middle of the range reported in the clinic.
- The tumor’s size in mammgraphy is linearly correlated with the post-surgical pathology size. When we linearly extrapolate our correlation across two orders of magnitude, it goes right through the middle of a cluster of 87 clinical data points.
- The tumor necrotic core has an age structuring: with oldest, calcified material in the center, and newest, most intact necrotic cells at the outer edge.
- The appearance of a “typical” DCIS duct cross-section varies with distance from the leading edge; all types of cross-sections predicted by our model are observed in patient pathology.
- The model also gave new insight on the underlying biology of breast cancer, such as:
- The split between the viable rim and necrotic core (observed almost universally in pathology) is not just an artifact, but an actual biomechanical effect from fast necrotic cell lysis.
- The constant rate of tumor growth arises from the biomechanical stress relief provided by lysing necrotic cells. This points to the critical role of intracellular and intra-tumoral water transport in determining the qualitative and quantitative behavior of tumors.
- Pyknosis (nuclear degradation in necrotic cells), must occur at a time scale between that of cell lysis (on the order of hours) and cell calcification (on the order of weeks).
- The current model cannot explain the full spectrum of calcification types; other biophysics, such as degradation over a long, 1-2 month time scale, must be at play.
I just posted a job opportunity for a postdoctoral researcher for computational modeling of breast, prostate, and metastatic cancer, with a heavy emphasis on calibrating (and validating!) to in vitro, in vivo, and clinical data.
If you’re a talented computational modeler and have a passion for applying mathematics to make a difference in clinical care, please read the job posting and apply!
(Note: Interested students in the Los Angeles/Orange County area may want to attend my applied math seminar talk at UCI next week to learn more about this work.)
The Macklin Math Cancer Lab is pleased to welcome Gianluca D’Antonio, a M.S. student of Luigi Preziosi and mathematician from Politecnico di Torino. Gianluca, who brings with him a wealth of expertise in biomechanics modeling, will spend 6 months at CAMM at the Keck School of Medicine of USC to model basement membrane deformation by growing tumors, biomechanical feedback between the stroma and growing tumors, and related problems. Gianluca’s interests and expertise fit very nicely into our broader vision of mechanistic cancer modeling, as well as USC / CAMM’s focus on applying the physical sciences to cancer (as part of the USC-led PSOC).
He is our first international visiting scholar, and we’re very excited for the multidisciplinary work we will accomplish together! So, please join us in welcoming Gianluca!
Next Monday (October 17, 2011), the USC-led Physical Sciences Oncology Center / CAMM will host a short course on multidisciplinary cancer modeling, combining the expertise of biologists, oncologists, and physical scientists. I’ll attach a PDF flyer of the schedule below. I am giving a talk during “Session II – The Physicist Perspective on Cancer.” I will focus on tailoring mathematical models from the ground up to clinical data from individual patients, with an emphasis on using computational models to make testable clinical predictions, and using these models a platforms to generate hypotheses on cancer biology.
The response to our short course has been overwhelming (in a good way), with around 200 registrants! So, registration is unfortunately closed at this time. However, the talks will be broadcast live via a webcast. The link and login details are in the PDF below. I hope to see you there! — Paul
7:00 am – 8:25 am : Registration, breakfast, and opening comments, etc.
David B. Agus, M.D. (Director of USC CAMM)
W. Daniel Hillis, Ph.D. (PI of USC PSOC, Applied Minds)
Larry A. Nagahara (NCI PSOC Program Director)
8:30 am – 10:15 am : Session I – Cancer Biology and the Cancer Genome
Paul Mischel, UCLA – The Biology of Cancer from Cell to Patient, Oncogenesis to Therapeutic Response
Matteo Pellegrini, UCLA – Evolution in Cancer
Mitchelll Gross, USC – Historical Perspective on Cancer Diagnosis and Treatment
10:30 am – 12:15 pm : Session II – The Physicist Perspective on Cancer
Dan Ruderman, USC – Cancer as a Multi-scale Problem
Paul Macklin, USC – Computational Models of Cancer Growth
Tom Tombrello, Cal-Tech – Perspective: Big Problems in Physics vs. Cancer
1:45 pm. – 3:10 pm : Session III – Novel Measurement Platforms & Data Management & Integration
Michelle Povinelli, USC – The Role of Novel Microdevices in Dissecting Cellular Phenomena
Carl Kesselman, USC – Data Management & Integration Challenges in Interdisciplinary Studies
3:10 pm – 3:40 pm : Session IV – Creativity in Research at the Interface between the Life and Physical Sciences
‘Fireside Chat’ David Agus and Danny Hillis, USC
4:00 pm – 5:00 pm : Capstone – Keynote Speaker
Tim Walsh, Game Inventor, Keynote Speaker
5:30 pm – 8:00 pm : Poster Session and Reception