[Re-Administration of Anti-EGFR Antibody Drugs for Unresectable Colorectal Cancer-Focusing on Tumor Markers].

The 2022 edition of the Guidelines for the Treatment of Colorectal Cancer described rechallenge therapy as a backward treatment for unresectable colorectal cancer, but currently, there is no evidence to support its benefit. We reviewed 6 cases of rechallenge therapy in which tumor marker trends could be followed in our department. Two cases had a rapid decline in tumor markers that was maintained for 7-8 months. In 3 cases, PR was also confirmed on imaging. In contrast, there was 1 case with no decrease in tumor markers at all. Our findings suggest that cases of wild-type RAS prior to rechallenge therapy and cases that are responsive to initial anti-EGFR antibody drugs may have been involved in the effect of rechallenge therapy.

Repeated partial tissue bite with inadequate cooling time for an energy device may cause thermal injury.

BACKGROUND: Over the past three decades, the use of ultrasonically activated device (USAD) and advanced bipolar device (ABD) has grown in minimally invasive surgeries. However, the thermal profile differences during repeated dissection with different grasping ranges of energy devices, which provide valuable information for preventing thermal injury by energy devices, remain unclear. METHODS: We developed an ex vivo benchtop model to examine the temperature profile of the blade and jaws of two USADs (HARMONIC® ACE + and Sonicision™) and a ABD (Ligasure™ Maryland) with different grasping ranges (partial tissue and full tissue bite) in repeated dissection with minimum cooling time. The maximum temperature, time required for completion to dissection of 10 cm of porcine muscle, thermal spread, and cooling time to reach 60 °C were continuously measured using video thermography. In addition, to evaluate one more grasping range "no tissue", we performed a stress test that activated the USAD without tissue intervention to assess the effects of excessive load on the blade and jaw. RESULTS: Repeated dissection of energy devices with minimal cooling time results in high blade and jaw temperatures proportional to the incision distance. In particular, the USADs with partial tissue bite showed a significantly higher temperatures at the blade and jaw, longer cooling times, and higher lateral thermal spread than those with a full tissue bite and the ABD. The stress test with a USAD showed an extremely high blade temperature exceeding 400 °C, with the tissue pad melting only 13.2 s after activation. CONCLUSION: Although USAD with partial tissue bite help ensure precise dissection, repeated long activation with inadequate cooling time may increase the risk of thermal injury during surgery. These results suggest that surgeons should use energy devices properly while understanding the risks of adjacent organ damage that could result from abuse of the device.

[A case of scirrhous gastric cancer responding to TS-1/CDDP neoadjuvant chemotherapy].

A 72-year-old female with scirrhous-type advanced gastric cancer was treated with TS-1/CDDP as neoadjuvant chemotherapy. TS-1 (80 mg/m(2)/day) was orally administered for 3 weeks and CDDP (60 mg/m(2)) was administered by intravenous drip on day 8. Partial response (PR) was obtained after the first course, and total gastrectomy was performed. The histological diagnosis revealed complete disappearance of cancer cells in the stomach and a few regional lymph node metastases (3/67). The patient has now been in good health without a recurrence for 1 year and 9 months after surgery.