David’s appendix cancer was not found because anyone was looking for appendix cancer. It was found during a colonoscopy. The pathology came back as goblet cell adenocarcinoma. Stage 3B. A right hemicolectomy followed.

Then the polyps started.

A year after his surgery, his surveillance colonoscopy turned up fourteen polyps. The next scope, six months later, found more. The one this past April found five, two of them precancerous. All of them were removed. The count has dropped enough that his care team has now moved him from a six-month schedule to a full year between scopes.

Then the same question surfaced from another corner of our world. Dr. Steve Himmelstein sits on the Appendicure board. He is also a goblet cell survivor. He had a colonoscopy recently, went looking for the connection between appendix cancer and colon polyps, and his wife Carol sent what he found to me. Two goblet cell survivors on the same small board, both looking this up within weeks of each other.

That is when this stopped being abstract for me. This is the exact thing patients and caregivers type into a search bar after a diagnosis or a scope: appendix cancer and colon polyps. They deserve a clear answer. The honest one has two parts that are easy to confuse, so it is worth taking them one at a time.

How appendix cancer and colon polyps are linked

The appendix branches off the cecum, the first part of the large intestine. Its inner lining follows the same basic pattern as the colon. That shared tissue is why a tumor in one place draws attention to the other. The foundational paper on this question notes that the appendix has a mucosal pattern similar to the colon, and that appendiceal adenocarcinoma may account for roughly one percent of all colorectal malignancies.

The link shows up when colon cancer comes first. The most cited figure comes from a 2007 study by Khan and Moran. In their series, about four percent of patients having colorectal cancer surgery were found to have an appendiceal tumor as well, ranging from benign cystadenomas to carcinoid tumors to cystadenocarcinomas. The rate is not settled. A larger series of 293 patients found under one percent. The honest read is that the true rate sits in a range, and it is high enough to matter. That same 2007 work noted that a person with colorectal cancer carries roughly a three percent risk of synchronous colonic neoplasia and a further two to three percent risk of a metachronous cancer down the line. That metachronous risk is the reason colon surveillance exists.

The link runs the other way too. Patients with appendiceal neoplasms show higher rates of colonic lesions than the general population. The signal is strongest for serrated lesions of the appendix, which are tied to synchronous colonic pathology at four times the general population rate and can be associated with serrated polyposis syndrome. Notably, those serrated lesions appear to follow a tumor pathway distinct from their colorectal counterparts. The diseases travel together, but that does not make them the same disease with the same biology.

One specific blind spot is worth naming. Polyps can sit at or near the appendiceal orifice, the small opening where the appendix meets the cecum. They are easy to miss on colonoscopy. Finding and removing them matters, because their removal can lower the risk of a future appendiceal or colorectal cancer. For anyone with appendix cancer in their history, this is a detail worth raising directly with the endoscopist before the next scope.

But it does not come back in the colon

This is the distinction that matters most, and the one that is easy to get wrong. When appendiceal cancer recurs, it does not return as colon polyps. It spreads first to the peritoneum, the lining of the abdominal cavity, then less often to the liver, and rarely to the lungs. This is the guidance Dr. JP Shen of MD Anderson, who serves on Appendicure’s medical advisory board, gave us directly. The published record agrees. A systematic review of more than 1,200 goblet cell adenocarcinoma cases found the most common sites of spread were the peritoneum, liver, small bowel, and ovaries, and that follow-up relies on surveillance CT scanning to monitor for recurrence.

So an appendix cancer patient is really being watched on two separate tracks. Imaging, usually CT, looks for recurrence in the abdomen. Colonoscopy looks for polyps and colon tumors. They answer different questions. The scan is the tool that monitors the appendix cancer. The colonoscopy is the tool that monitors the colon.

For David, that reframes everything. The polyps his colonoscopies keep finding are not his appendix cancer returning. They are colon polyps, caught and removed on schedule. His appendix cancer is tracked by the scans, not the scopes. As I write this, David and I are on a plane from North Carolina to MD Anderson in Texas for those scans. That trip, not the colonoscopy, is how we watch for the thing that could actually come back. Knowing which test does which job changes how you read a polyp result. It is a routine finding, not the cancer coming back.

What this means for you

Two kinds of surveillance are doing two different jobs. Imaging watches for recurrence in the peritoneum, liver, and beyond. Colonoscopy watches the colon, because the association between appendiceal tumors and colonic polyps is real and runs both ways. Guidelines are beginning to say the second part out loud. The German consensus guideline for low-grade appendiceal mucinous neoplasms and pseudomyxoma peritonei now recommends a screening colonoscopy to rule out synchronous colorectal tumors.

None of this is a reason to panic when polyps turn up on a scope. Polyps found and removed are polyps that cannot become something worse. And because appendix cancer does not recur in the colon, a polyp on a colonoscopy is not the cancer coming back. David is currently NED, confirmed by the imaging that actually tracks his disease. The colonoscopies that keep finding polyps are doing a separate and important job of their own.

Ask your care team two questions. How often should I be scanned, and how often should I be scoped. The answers are not the same, and they are not for the same reason.

I will be honest about where this leaves me. David’s team moved him to a one-year interval because his polyp count fell and the precancerous ones came out cleanly. David is relieved. I am not there yet. After watching those counts, I would feel safer at six months. His next scope is a year out, and that wait is the part I cannot make peace with. I would rather raise it with his care team than sit on it for twelve months. That gap between us is the real texture of cancer surveillance. The schedule is a judgment call, the two people living it do not always feel it the same way, and asking your care team to explain their reasoning is always fair.

Why the registry exists

David and Steve are two people. To a researcher, they are also two data points, and two data points cannot answer the questions they were both asking about appendix cancer and colon polyps. How often do polyps recur after a hemicolectomy for a goblet cell tumor. Which subtypes carry the most colonic risk. How should surveillance be timed for appendix cancer specifically rather than borrowed from colon protocols. Appendix cancer is rare enough that no single clinic sees the volume needed to find those patterns.

That is the gap a patient-led registry is built to close. When enough patients and caregivers put what they know in one place, single cases start to add up to something researchers can actually use. The questions Steve typed into a search bar after his colonoscopy are exactly the ones a registry can eventually answer with numbers instead of guesses.

This article is for education and is not medical advice. Talk with your own care team about the surveillance schedule that is right for you.

Sources: Khan MN, Moran BJ. Dis Colon Rectum. 2007;50(11):1856-1859. · Lohsiriwat V, et al. World J Surg Oncol. 2009;7:51. · Rossi RE, et al. J Surg Oncol. 2023. · Reid MD, et al. Mod Pathol. 2016;29(10):1243-1253. · Goblet cell adenocarcinoma systematic review, Front Oncol. 2022;12:915028. · German S2k guideline on LAMN, Eur J Cancer. 2025.