He inquires if the innkeeper’s dog bites, and the elderly man blandly replies, “No”. Clouseau reaches down to pet the dog, which promptly nips his hand.
“I thought you said your dog does not bite!” complains Clouseau.
“That is not my dog,” calmly replies the innkeeper.
I love dogs. No matter how my day went at work, I have a happy homecoming when greeted joyfully by my pack of pooches. While dogs are great fun, playful, and wonderful companions, they can also chew your expensive new shoes to pieces or leave malodorous droppings in the house that you follow your nose to find. Dogma is much like this. Dogma develops because a part of human nature likes to embrace things that are known, familiar, and comfortable. But dogma, like dogs, can be destructive or problematic. Dogma can suppress or discourage thoughtfulness and innovation. This is particularly dangerous if dogma is supported by senior leaders and the climate does not support or encourage questioning of the entrenched beliefs. In cancer care, dogma can be potentially deadly if we involved in patient care and research don’t constantly remind ourselves to question the adequacy of currently available treatments, because we clearly do not cure all of the patients we treat.
In surgical oncology, dogma can develop as readily as in any other area of medicine. As a poignant example, in 1988 a paper was published describing the survival rate of patients with colorectal cancer liver metastases that were surgically removed (Resection of the liver for colorectal carcinoma metastases: a multi-institutional study of indications for resection. Surgery 1988; 103(3): 278-288). The authors of this paper reported that one third of patients who underwent complete surgical removal of their liver tumors were still alive five years after the operation. The disease-free survival rate of these patients studied retrospectively was 25%, meaning that most of the patients who survived to the five year mark were not only alive, but had no evidence of recurrent colorectal cancer. This paper is a seminal reason why surgical treatment of colorectal cancer liver metastases, stage IV disease, is a common practice today. Some patients with colorectal cancer will have it spread only to their livers. In these patients, we can improve their probability of long-term survival by surgically removing or destroying the malignant liver tumors. While this paper was very important in demonstrating the role for surgical treatment of colorectal cancer liver metastases, it was also responsible for establishing surgical dogma. The authors reported that patients who had four or more liver metastases were less likely to derive a survival benefit from surgical treatment and, therefore, surgical treatment was relatively contra-indicated. “Relatively” is relatively open to interpretation and because patients with four or more metastases had a relatively poor prognosis compared to those patients with three or fewer metastases, surgery was considered too high a risk for too small a gain. When I was a surgical oncology fellow, this alpha dogma ruled. I saw several patients in clinic who had four or more liver metastases that were technically resectable, meaning all could be removed while leaving a volume of normal liver adequate for the patient to survive. However, we referred them to our medical oncology colleagues for chemotherapy treatment because they had “too many tumors”, which dogmatically was believed to represent more aggressive, non-surgical disease.
I think it is critical that we self-examine our patterns of behavior and our practice on a regular basis to stay on the cutting edge of treatment and to consider if we can safely push the envelope to help our patients. As my fellowship in surgical oncology progressed, I went back and carefully re-read the 1988 paper. In the discussion section, I was surprised to see that the authors reported that patients who had four or more liver metastases had a five-year survival rate of 17%, which was indeed inferior to the 33% that they reported for all patients in the series. This led to their recommendation that patients with four or more lesions not be considered for surgical treatment. This confounded me because a 17% five-year survival rate was still better than the essentially 0% five-year survival rate in patients who did not undergo surgical treatment in an era when we had very few effective chemotherapy drugs for stage IV colorectal cancer.
Early in my career, after completing my fellowship training, I decided that adhering to this dogma did not make sense to me. I knew we could perform major liver operations with a low risk of life-threatening complications in our patients. I initiated a prospective hepatobiliary tumor surgery database and carefully followed all of the patients we treated. I saw patients with stage IV colorectal cancer confined to the liver and would consider them for surgical treatment that included removal of all tumors when possible, or a combination of removal and killing additional small tumors with techniques that heated the tumors (radiofrequency ablation) when complete surgical removal was not feasible. These patients were then followed, as are all of our cancer patients, on a routine basis over the course of their lives.
I tell medical students, residents, and fellows who work with me to question dogmatic practices and beliefs routinely. Challenging dogma certainly led to a difference in the lives of some of the patients I treated early in my career. In 2006 we published a paper on 151 patients with more than four colorectal cancer liver metastases that were treated surgically (Debunking dogma: surgery for four or more colorectal liver metastases is justified. Journal of Gastrointestinal Surgery 2006; 10: 240-248). We found that 51% of our patients were still alive five years after their surgical treatment. The number of patients who were disease-free was only 22%, meaning that the remaining 29% who survived five years after surgical treatment had developed recurrence of their cancer, but were still alive and receiving additional treatments. We learned the probability of long-term survival was improved by combining surgical treatment with use of active chemotherapy agents before the operation. Importantly, there are lots of surgeons and physicians in the world who constantly investigate and look for better options to treat our patients. Around the time of our report in 2006, numerous surgical groups around the world described their experience and confirmed that surgical treatment of four or more colorectal cancer liver metastases could improve the survival rate of patients. Critical thinking and asking questions is in our professional DNA, we all want better results for our patients!
We can never predict exactly what will happen with any specific patient. I have two examples from my group of patients with more than four colorectal cancer liver metastases who I treated with major liver operations despite the dogma that developed after the 1988 paper. Both were treated in 1995, both were men in their mid-50’s who were successful professionals. One man had seven colorectal cancer liver metastases, all in the right lobe of his liver. I cannot speculate why his tumors grew only in the right lobe of his liver, but that is the situation which presented itself to me when I first viewed his CT scans. I removed the right lobe of his liver, which comprised about two thirds of his total liver volume, and he recovered from the operation uneventfully. He told me his goal at the time of surgery was to see his three children graduate from high school and college. I diligently informed him that I could offer no guarantees on achieving that goal and assured him I would follow him closely and intercede should his cancer recur. This year he became a 20-year survivor after surgical removal of his colorectal cancer liver metastases. He attended three high school and three college graduations, and has gone on to see all three of his children married. He is now enjoying retirement, spending time with his wife, and spoiling his grandchildren.
The second gentleman does not have a story with a similar happy ending. He had five colon cancer liver metastases that were located in both lobes of the liver. It was possible to remove all five tumors with a combination of wedge and segmental resections. During his operation, as I do in all liver operations, I performed an intraoperative ultrasound on his liver. This is the ultimate diagnostic tool of the hepatobiliary surgical oncologist because we can lay the probe directly on the liver and detect additional tumors that are too small to be seen on CT or MRI scans. We discovered that in about 6% of our patients, we find one or two additional small tumors with the ultrasound that we did not see on the preoperative imaging studies. In this man, I found only the five tumors that were seen on his preoperative CT scan. Similar to the previous patient, he was in the hospital for only six days after the procedure and recovered uneventfully. Like my first patient, pathology confirmed that all tumors had been completely removed with a good margin of normal tissue away from the tumors. This patient represents one of the more frightening phenomena we sometimes encounter in surgical oncology. I saw both of these patients back three months after their operation for the first post-operative CT scan. Unlike my 20 year survivor of resection of seven metastases who has never had recurrence of his cancer, I was shocked when I looked at the three month post-operative images on my second patient. He had six new 1.0-1.5 cm diameter liver metastases. I was flummoxed because I had just evaluated his liver three months earlier with the best diagnostic tool we have available. Intraoperative ultrasound can detect small tumors, but we have no test that reveals microscopic nests of cancer cells in the liver or in other organs. Clearly, the new tumors that we visualized on a CT scan only three months after his liver operation were present microscopically when I performed the surgical procedure, I simply could not detect them. Unfortunately, his cancer grew at a meteoric pace and he survived only another seven months while being treated with chemotherapy.
I say it to every patient; I cannot predict your future. Obviously, stories like the first patient who is a 20 year survivor after surgical treatment of stage IV colorectal cancer is invigorating. The disappointment and angst represented by the second patient points out the importance of continuing to push for more basic and clinical research and better therapeutic combinations to improve the outcomes of our cancer patients.
`The take home message is dogma can be comfortable and can lull us into a sense of security. We may invoke dogma to support decisions keeping us inside of our comfort zone. I believe dogma should be questioned continually and comfort zones should be abandoned and demolished on a regular basis.
Probe. Inquire. Cogitate. Imagine. Dream. Attempt. Experiment. Push. Question. Always question.
“I thought you said your dogma does not bite?”
“That is not my dogma.”
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Article last time updated on 31.01.2017.