Brazilian Society of Surgical Oncology: Guidelines for the management of anal canal cancer

BACKGROUND

Anal canal squamous cell carcinoma (SCC) is a relatively uncommon neoplasia, and it is mostly a local-regional cancer, of low metastatic potential (only 15%), resulting in cure in most cases treated with definitive chemoradiation. On the other hand, its incidence has been steadily increasing over the last decades, which makes it an important public health problem. In an effort to provide surgeons and oncologists who treat patients with anal cancer with the most updated information based on the best scientific evidence, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guideline for the management of anal canal SCC, focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the management of anal canal squamous cell carcinoma (SCC) based on current scientific evidence.

METHODS

Between October 2022 and January 2023, 14 experts met to develop the guidelines for the management of anal canal cancer. A total of 30 relevant topics were distributed among the participants. The methodological quality of a final list with 121 sources was evaluated, all the evidence was examined and revised, and the management guidelines were formulated by the 14-expert committee. To reach a final consensus, all the topics were reviewed in a meeting that was attended by all the experts.

RESULTS

The proposed guidelines contained 30 topics considered to be highly relevant in the management of anal canal cancer, covering subjects related to screening recommendations, preventive measures, tests required for diagnosing and staging, treatment strategies, response assessment after chemoradiotherapy, surgical technique-related aspects, and follow-up recommendations. In addition, screening and response assessment algorithms, and a checklist were proposed to summarize the important information and offer an updated tool to assist surgeons and oncologists who treat anal canal cancer and in providing the best care to their patients.

CONCLUSION

These guidelines summarize recommendations based on the most current scientific evidence on relevant aspects of anal canal cancer management and are a practical guide to help surgeons and oncologists who treat anal canal cancer make the best therapeutic decisions.

Myokines in treatment-naïve patients with cancer-associated cachexia

Cancer-associated cachexia is a complex metabolic syndrome characterized by weight loss and systemic inflammation. Muscle loss and fatty infiltration into muscle are associated with poor prognosis in cancer patients. Skeletal muscle secretes myokines, factors with autocrine, paracrine and/or endocrine action, which may be modified by or play a role in cachexia. This study examined myokine content in the plasma, skeletal muscle and tumor homogenates from treatment-naïve patients with gastric or colorectal stages I-IV cancer with cachexia (CC, N = 62), or not (weight stable cancer, WSC, N = 32). Myostatin, interleukin (IL) 15, follistatin-like protein 1 (FSTL-1), fatty acid binding protein 3 (FABP3), irisin and brain-derived neurotrophic factor (BDNF) protein content in samples was measured with Multiplex technology; body composition and muscle lipid infiltration were evaluated in computed tomography, and quantification of triacylglycerol (TAG) in the skeletal muscle. Cachectic patients presented lower muscle FSTL-1 expression (p = 0.047), higher FABP3 plasma content (p = 0.0301) and higher tumor tissue expression of FABP3 (p = 0.0182), IL-15 (p = 0.007) and irisin (p = 0.0110), compared to WSC. Neither muscle TAG content, nor muscle attenuation were different between weight stable and cachectic patients. Lumbar adipose tissue (AT) index, visceral AT index and subcutaneous AT index were lower in CC (p = 0.0149, p = 0.0455 and p = 0.0087, respectively), who also presented lower muscularity in the cohort (69.2% of patients; p = 0.0301), compared to WSC. The results indicate the myokine profile in skeletal muscle, plasma and tumor is impacted by cachexia. These findings show that myokines eventually affecting muscle wasting may not solely derive from the muscle itself (as the tumor also may contribute to the systemic scenario), and put forward new perspectives on cachexia treatment targeting myokines and associated receptors and pathways.