Letter to the Editor: Objective Assessment of Surgical Restaging after Concurrent Chemoradiation for Locally Advanced Pancreatic Cancer

To the Editor:

I have read with interest the study "Objective Assessment of Surgical Restaging after Concurrent Chemoradiation for Locally Advanced Pancreatic Cancer" by Paik et al. (1). The article shares the experince of neoadjuvant concurrent chemoradiation therapy (CCRT) in locally advanced pancreatic cancer (LAPC) which authors conclude as preoperative CCRT in LAPC rarely leads to surgical downstaging, and it could lower resectability rates.

In the manuscript, the authors state that "During follow-up, 46 patients (85%) died and the median overall survival was 16.2 (95% CI 12.7-19.7) months. Disease progression was observed in 47 patients (87%) and the median progression-free survival was 6.4 months (95% CI 4.0-8.8) (Fig. 2B). Among the patients with disease progression, systemic presentations (36 patients, 77%) were more frequent than local progression (11 patients, 23%)."

I have several comments to make on this article. First, I saw in the manuscript that none of the patients had pre-treatment staging either by open or laparoscopic surgery, although 94% of the patients were in Stage 3. Although CT/MR can diagnose apparent metastasis, current axial imaging is limited when it comes to completely visualized potentially small peritoneal and distant tumor deposits (2, 3). Studies have shown that a certain number of Stage 3 patients are diagnosed with minute peritoneal or distant metastasis when a staging laparoscopy is performed (3, 4, 5). In addition, locally advanced pancreatic cancer patients have a high incidence of positive intraoperative peritoneal lavage cytology, which unfortunately has a similar survival rate to that of patients with metastasis if treated locoregionally (6, 7). In particular, some of these patients are actually in Stage 4, but we treat them as Stage in whom chemoradiation therapy would not add any survival benefit.

Second, this study included more systemic presentations (36 patients, 77%) than local progression (11 patients, 23%) among the patients with disease progression. Fig. 2B shows that nearly 60% of the patients had systemic presentations within 6 months, which is really a short period of time to have that number of systemic presentations in Stage 3 though treatment (1). The author's findings also support the possibility that the patients could have minute peritoneal or distant metastasis or that they could have positive intraoperative peritoneal lavage cytology if performed before concurrent chemoradiation therapy.

Third, any patients diagnosed with peritoneal metastasis or positive intraoperative peritoneal lavage cytology can be candidates for intraperitoneal therapy (7).

In conclusion, staging laparoscopy is strictly recommended in locally advanced pancreatic adenocarcinoma patients before accepting these patients as Stage 3 and initiating any locoregional therapy. This will allow accurate therapy and staging.