Assessing neoadjuvant therapy recommendations in 19 national and international guidelines for rectal cancer.

BACKGROUND:  Treatment guidelines belong to the most authoritative sources of evidence-based medicine and are widely implemented by health-care providers. Rectal cancer with an annual incidence of over 730,000 new cases and nearly 340,000 deaths worldwide, remains a significant therapeutic challenge. The total mesorectal excision (TME) leads to a dramatic improvement of local control. The addition of neoadjuvant treatment has been proposed to offer further advancement. However, this addition results in significant functional impairment and a decline in the quality of life. METHODS: This review critically assesses whether the recommendation for neoadjuvant treatment in current international guidelines is substantiated. A comprehensive search was conducted in July 2022 in PubMed resulting in 988 papers published in English between 2012 and 2022. After exclusions and proofs 19 documents remained for further analysis. RESULTS: Of the 19 guidelines considered in this review, 11 do not recommend upfront surgery, and 12 do not address the issue of functional impairment following multimodal treatment. The recommendation for neoadjuvant therapy relies on outdated references, lacking differentiated strategies based on current utilisation of MRI staging; numerous guidelines recommend neoadjuvant treatment also to subgroups of patients, who may not need this therapy. Also statements regarding conflicts of interest are often not presented. CONCLUSIONS: An immediate and imperative step is warranted to align the recommendations with the latest available evidence, thereby affording rectal cancer patients a commensurate standard of care. A meticulous assessment of the guideline formulation process has the potential to avert heterogeneity in the future.

Challenges and solutions in 3D printing for oncology: a narrative review.

BACKGROUND AND OBJECTIVE: Oncology is increasingly adopting three-dimensional (3D) printing, a method of creating objects through additive manufacturing using various techniques and materials. This technology, divided into conventional 3D printing (using non-biological materials like thermoplastics or titanium) and bioprinting (involving living cells and tissues), has shown potential in surgical planning, implant creation, and radiotherapy. However, despite promising preclinical and clinical applications, its clinical integration faces challenges such as a lack of strong evidence, standardized guidelines, and detailed data on costs and scalability. This study reviews the current use of 3D printing in oncology, aiming to differentiate between practical and experimental applications, thereby guiding clinicians interested in incorporating this technology. METHODS: A literature search was conducted to gather comments, reviews, and preclinical and clinical studies focusing on the use of 3D printing in oncology, with publications dated before December 1, 2023. The search for pertinent studies involved utilizing PubMed and Google Scholar Review. The selection process for articles was based on a unanimous consensus among all authors. We excluded topics related to bioprinting and the technical nuances of 3D printing. KEY CONTENT AND FINDINGS: The review comprehensively describes the utilization of 3D printing in radiation oncology, surgical oncology, orthopedic oncology, medical oncology, hyperthermia, and patients' education. However, 3D printing faces several limitations that are related to unpredictable costs, difficult scalability, very complex regulations and lack of standardization. CONCLUSIONS: 3D printing is increasingly useful in oncology for diagnostics and treatment, yet remains experimental and case-based. Despite growing literature, it focuses mostly on pre-clinical studies and case reports, with few clinical studies involving small samples. Thus, extensive research is needed to fully evaluate its efficacy and application in larger patient groups.

Prognostic Value of Metastatic Lymph Node Ratio and Identification of Factors Influencing the Lymph Node Yield in Patients Undergoing Curative Colon Cancer Resection.

Due to the impact of nodal metastasis on colon cancer prognosis, adequate regional lymph node resection and accurate pathological evaluation are required. The ratio of metastatic to examined nodes may bring an additional prognostic value to the actual staging system. This study analyzes the identification of factors influencing a high lymph node yield and its impact on survival. The lymph node ratio was determined in patients with fewer than 12 or at least 12 evaluated nodes. The study included patients after radical colon cancer resection in UICC stages II and III. For the lymph node ratio (LNR) analysis, node-positive patients were divided into four categories: i.e., LNR 1 (<0.05), LNR 2 (≥0.05; <0.2), LNR 3 (≥0.2; <0.4), and LNR 4 (≥0.4), and classified into two groups: i.e., those with <12 and ≥12 evaluated nodes. The study was conducted on 7012 patients who met the set criteria and were included in the data analysis. The mean number of examined lymph nodes was 22.08 (SD 10.64, median 20). Among the study subjects, 94.5% had 12 or more nodes evaluated. These patients were more likely to be younger, women, with a lower ASA classification, pT3 and pN2 categories. Also, they had no risk factors and frequently had a right-sided tumor. In the multivariate analysis, a younger age, ASA classification of II and III, high pT and pN categories, absence of risk factors, and right-sided location remained independent predictors for a lymph node yield ≥12. The univariate survival analysis of the entire cohort demonstrated a better five-year overall survival (OS) in patients with at least 12 lymph nodes examined (68% vs. 63%, p = 0.027). The LNR groups showed a significant association with OS, reaching from 75.5% for LNR 1 to 33.1% for LNR 4 (p < 0.001) in the ≥12 cohort, and from 74.8% for LNR2 to 49.3% for LNR4 (p = 0.007) in the <12 cohort. This influence remained significant and independent in multivariate analyses. The hazard ratios ranged from 1.016 to 2.698 for patients with less than 12 nodes, and from 1.248 to 3.615 for those with at least 12 nodes. The LNR allowed for a more precise estimation of the OS compared with the pN classification system. The metastatic lymph node ratio is an independent predictor for survival and should be included in current staging and therapeutic decision-making processes.