Oncology Day 2/4 - Sandy

Today in the morning, Dr. Chen gave us (Bor-Han, Amanda and I) an informal presentation on colon cancer and in the afternoon, we observed him seeing patients in the outpatient clinic.

Colorectal cancer is the most common cancer in Taiwan – it occurs most frequently in the rectum, followed by sigmoid and ascending colon. Dr. Chen told us a case about a patient with colon cancer metastasized to the liver, and the conversion therapy available that can change this originally unresectable, advanced-staged liver metastasis to being resectable after chemotherapy. The patient would take a combination of drugs with different mechanisms, including 5 FU, leucovorin, irinotecan and oxaliplatin. Although the success rate is humble, about 20-30% of the trials are successful, the result is still promising. And from this data, Dr. Chen reminded us that a tumor is heterogenous, and we must always keep in mind about the possibility of drug resistance when treating our patients in the future.

We talked about how many cycles of chemotherapy are required to control a tumor, and Dr. Chen explained to us in-depth of how an average of 4-6 cycles of chemotherapy for a cancer patient came about. One cm of tumor is approximately 10^9 cells and our goal is to shrink a tumor to be less than 10^4 cells, as that is when our immune system would have control over it. Ever cycle of chemo kills about 90% of 1 log of cells, so it would take about 5 cycles of cells to shrink the tumor down to manageable size. To be confident that the tumor has shrunk, 6 cycles of chemotherapy are typically performed. Dr. Chen’s insightful explanation was excellent, and it is this kind of in-depth analysis of oncology that fascinates me as my mind begs for more.

Ironically, Dr. Chen reminded us not to be so focus to learn about learning the details and focus on the big picture instead. He said that the most important thing to learn about is to observe his bedside manner, learn the clinical symptoms, and we will have the rest of our lives to learn about the nitty-gritty, unending details of medicine. I really admire Dr. Chen’s attitude, as he employs an easy going personality and a broad perspective on medicine. His expertise in both science and clinical medicine earns him the affection of many patients – they showered him with gift certificates to restaurant and coffees for his staff. He generously gave the three of us all the coffees to bring home and we thanked him. In the back of my mind, I hope to be as respected as he is of a physician, someday.