Gallbladder Cancer & Hepatic Resection: Is it Necessary?
In honor of February being bile duct and gallbladder cancer month, this post will talk about a new study published in World Journal of Surgical Oncology, entitled “Validation of the oncologic effect of hepatic resection of T2 gallbladder cancer: a retrospective study.” Check out the journal article here.
For this post, I spent some time speaking with Dr. Arnold Cohen—a Harvard, U Penn, and Northwestern trained gastroenterologist of nearly 40 years who has spent much of his career working with gallbladder cancers and diseases. He offered insight, advice, and perspective on both gallbladder cancer care and the findings of this study. If you want to hear what he has to say on gallbladder cancer, hepatic resection, and future directions, check out the audio files both within and at the end of this post!
A little bit of basic background on gallbladder cancer: less than 5000 new cases are diagnosed each year, and it is usually found incidentally when patients are undergoing surgery for cholelithiasis (gall stones). While the prevalence of gallbladder cancer varies in regions throughout the globe, it remains proportional to the prevalence of cholelithiasis (studies have shown that gallstones increases the likelihood of developing gallbladder cancer). However, it should be noted that there is only a 0.5% incidence of gallbladder cancer in those with cholelithiasis.
This is where the gallbladder is:
The TNM staging system is used to stage gallbladder cancer, just as in other types of cancer.
One notable difference is for cancer diagnosed in stage 2 (T2). T2 is sub classified into T2a and T2b, with T2a indicating a tumor located on the peritoneal side of the gallbladder and T2b indicating a tumor located on the hepatic side of the gallbladder. T2a tumors may progress to T3 without ever being classified as T2b. Nearly 60% of gallbladder tumors are diagnosed in T2, with about 61% peritoneal (T2a) and 39% hepatic (T2b).
Overall, gallbladder cancer has a relatively poor prognosis due to the late stage at diagnosis, a problem compounded by both the challenging anatomic location of the gallbladder and the vagueness and nonspecificity of symptoms prior to diagnosis. However, gallbladder cancers diagnosed in an early stage of disease has a high survival rate.
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For T2 gallbladder cancer, current standard of care includes surgical removal of the gallbladder and partial resection of the liver-—this surgery is known as extended cholecystectomy. Watch the surgery on YouTube here.
Cho et al. found that hepatic resection was not essential in the curative treatment of T2 gallbladder cancer, regardless of tumor size. The authors also recommended that a more systemic approach for gallbladder cancer treatment be taken.
The study retrospectively looked at patients diagnosed with T2 gallbladder cancer, with some patients having undergone extended cholecystectomy and some having undergone cholecystectomy with no hepatic resection. The authors state that “there were no significant differences in preoperative conditions, tumor markers, complications, tumor size, and T stage between the [hepatic resection] group and the non-[hepatic resection] group.” The data showed that there was no statistically significant difference in survival time between patients who underwent hepatic resection and those who did not, even when stratified into T2a and T2b. They also found that patients who underwent hepatic resection had significantly longer operation times and significantly longer hospital stays than the patients that did not undergo hepatic resection. In their discussion, Cho et al. specified that while hepatic resection was not a significant predictor of prognosis, other factors such as lymph node involvement and tumor location were significant predictors.
This study is one of many that considers a relatively new (historically speaking)—but ever growing—aspect to cancer care: the consideration of the “whole person.” If further studies support the conclusion drawn in this paper—that hepatic resection is unnecessary for curative treatment of T2 gallbladder cancer—these patients could have fewer or shorter surgeries*, shorter hospital stays, fewer complications, and lower healthcare costs.
Some of the problems faced in this study were inevitable due to the ethical problem of not providing a patient the standard of care procedure for the purpose of research, leading to non-equivalent and non-representative groups of patients. This study did not discuss reasons that patients with T2 gallbladder cancer may not undergo hepatic resection, but Dr. Cohen stated that these reasons may include: having comorbidities that fit the exclusion criteria, surgeons or surgery centers not equipped for extended cholecystectomy, tumors that are deemed distant enough from the liver so as not to pose a risk for micro mets, and patient refusal. Each of these factors could easily affect the validity and reliability of the results if not controlled for.
Additionally, the study may have been underpowered in its data and analysis. As a delineation of the four patient categories (T2a with hepatic resection, T2a without hepatic resection, T2b with hepatic resection, T2b without hepatic resection) was not provided, it would be difficult to determine the strength of the study and of the results.
As stated in the study, future studies with more patients should be done. These studies should work to eliminate potential confounding factors related to hepatic resection and complications. In an ideal world, imaging would be able to pick up any micro mets in the liver to indicated whether or not hepatic resection in necessary. Alternatively, future chemotherapies could target these micro mets, reducing the need for hepatic resection while also decreasing the risk of any remaining cancer.
Most times, gallbladder cancer is found incidentally upon removal of the gallbladder for some other reason, typically gallstones. These patients—once the pathology for the gallbladder has been returned and is positive for gallbladder cancer and the patient has undergone scans to look for any metastases and has been appropriately staged—undergo a second surgery to extend the previous cholecystectomy by removing a few centimeters of liver tissue. In the more uncommon scenario where patients have already been diagnosed with T2 gallbladder cancer, hepatic resection increases the surgery length from that of a simple cholecystectomy.
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