Tattooing colorectal lesions assists with lymph node harvesting, identifying tumor cells

WASHINGTON — Endoscopic tattooing in colorectal carcinomas prior to surgery can improve finding the lymph nodes that are most prone to harbor tumor cells in addition to lymph node harvesting, according to a Spanish study presented at DDW 2015.

Perspective from Arslan Kahloon, MD

“There’s a big, big problem,” Miriam Cuatrecasas, MD, PhD, a pathologist at the Hospital Clinic de Barcelona, said during her presentation. “More than 99% of the lymph node tissue is not analyzed and depending on the study there’s a tumor location bias between 11% and 24%. So the consequences are lymph node metastases are not being detected and we are diagnosing false negative patients.”

It is difficult to procure 12 lymph nodes in small colectomies that are performed in early colon cancers, so Cuatrecasas and colleagues conducted this study to determine differences in molecular detection of CK19 mRNA in a colorectal tumor from the drainage nodal basin based on if lymph modes were tattooed or not. Additionally, the researchers wanted to determine if pre-surgery endoscopic tattooing would enhance lymph node harvesting.

Lymph node dissection took place in 69 colon tumors that were surgically extracted. Endoscopic tattooing took place in 65% of those tumors prior to surgery with a median of 63 days (range, 37-91) between both events.

From the 69 patients, researchers collected 1,139 lymph nodes. From those nodes, 79.6% were freshly dissected and analyzed. A significantly higher amount of lymph nodes were discovered in tattooed specimens (median, 17 lymph nodes), than in non-tattooed specimens (median, 14.5; P = .026). There was also a greater total of fresh lymph nodes found in the tattooed specimens (median, 13) than in non-tattooed specimens (median, 10.5; P = .02). The colectomy specimens were small, averaging 14 cm in length (range 11-18).

One-step nucleic acid amplification was used to determine that 10% of the freshly dissected lymph nodes were positive and came from 40 of the original patients (58%) and only 4 (10%) of those patients had macrometastases.

Among the tattooed specimens, 60% of the lymph nodes that were positive had been tattooed prior to surgery while less than 7% of non-tattooed lymph nodes were positive.

Cuatrecasas suggested tattooing every colon cancer to increase lymph node harvesting.

“That’s my proposal,” she said. “The patient deserves that we get all the lymph nodes that may harbor a tumor.” – by Anthony SanFilippo

For more information: Cuatrecasas, M, et al. Abstract 97. Presented at: Digestive Disease Week; May 15-19, 2015; Washington, D.C.

Disclosure: Cuatrecasas reported no relevant financial disclosures. See the faculty disclosure index on the DDW website for a full list of disclosures.

Perspective

Arslan Kahloon, MD

We always kind of tattoo most of the lesions that we already have if they actually end up going to surgery. However, the biggest question that has been asked is, ‘If you do intra-lesional injections of a tattoo into the tumor aren’t you theoretically altering the mucosa?’ That could lead to micro-metastases. That literature has not panned out as to what the right answer is for that. All the data that Cuatrecasas presented, showed if you put tattoos too far out then harvesting of the lymph nodes goes down anyway and it would make no difference, but if you do tattoo the tumor, the risk of micro-metastases goes up, so it’s hard to say which approach would really work. It’s still an area which requires more investigation, however most of the literature and work being done in the United States shows the surgeons try to resect as much colon and not a limited resection, which solves the problem and you wouldn’t need an intra-lesional injection. But, it is one neat idea.

Arslan Kahloon, MD

University of Tennessee

Disclosures: Kahloon reports no relevant financial disclosures.