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.

Rectal Cancer: Are 12 Lymph Nodes the Limit?

Lymph node dissection is a crucial element of oncologic rectal surgery. Many guidelines regard the removal of at least 12 lymph nodes as the quality criterion in rectal cancer. However, this recommendation remains controversial. This study examines the factors influencing the lymph node yield and the validity of the 12-lymph node limit. Patients with rectal cancer who underwent low anterior resection or abdominoperineal amputation between 2000 and 2010 were analyzed. In total, 20,966 patients from 381 hospitals were included. Less than 12 lymph nodes were found in 20.53% of men and 19.31% of women (p = 0.03). The number of lymph nodes yielded increased significantly from 2000, 2005 and 2010 within the quality assurance program for all procedures. The univariate analysis indicated a significant (p < 0.001) correlation between lymph node yield and gender, age, pre-therapeutic T-stage, risk factors and neoadjuvant therapy. The multivariate analyses found T3 stage, female sex, the presence of at least one risk factor and neoadjuvant therapy to have a significant influence on yield. The probability of finding a positive lymph node was proportional to the number of examined nodes with no plateau. There is a proportional relationship between the number of examined lymph nodes and the probability of finding an infiltrated node. Optimal surgical technique and pathological evaluation of the specimen cannot be replaced by a numeric cut-off value.

Treatment and survival of rectal cancer patients over the age of 80 years: a EURECCA international comparison.

BACKGROUND: The optimal treatment strategy for older rectal cancer patients remains unclear. The current study aimed to compare treatment and survival of rectal cancer patients aged 80+. METHODS: Patients of ≥80 years diagnosed with rectal cancer between 2001 and 2010 were included. Population-based cohorts from Belgium (BE), Denmark (DK), the Netherlands (NL), Norway (NO) and Sweden (SE) were compared side by side for neighbouring countries on treatment strategy and 5-year relative survival (RS), adjusted for sex and age. Analyses were performed separately for stage I-III patients and stage IV patients. RESULTS: Overall, 19 634 rectal cancer patients were included. For stage I-III patients, 5-year RS varied from 61.7% in BE to 72.3% in SE. Proportion of preoperative radiotherapy ranged between 7.9% in NO and 28.9% in SE. For stage IV patients, 5-year RS differed from 2.8% in NL to 5.6% in BE. Rate of patients undergoing surgery varied from 22.2% in DK to 40.8% in NO. CONCLUSIONS: Substantial variation was observed in the 5-year relative survival between European countries for rectal cancer patients aged 80+, next to a wide variation in treatment, especially in the use of preoperative radiotherapy in stage I-III patients and in the rate of patients undergoing surgery in stage IV patients.

Surgical Quality in Rectal Cancer Management: What Can Be Achieved by a Voluntary Observational Study?

PURPOSE: Countries with nationwide quality programmes in colorectal cancer report an improved outcome. In Germany, a self-organized and self-financed observational quality assurance project exists, based on voluntary participation. The object of the present study was to ascertain whether this nationwide project also improves the outcome of colorectal cancer. METHODS: The German Quality Assurance in Colorectal Cancer Project started in 2000 and by 2012 contained 85,000 patients. Inclusion criteria for the study were participation for the entire period of 13 years and treatment of rectal cancer. The following parameters were analysed: (1) patient related: age, gender, ASA classification, T-stage, and N-stage, (2) system related: frequency of preoperative CT and MRI, and (3) outcome related: CRM status, complications, and hospital mortality. RESULTS: Forty-one of the 345 hospitals treating 11,597 patients fulfilled the inclusion criteria. The median age increased from 67 to 69 years (p = 0.002). ASA stages III and IV increased from 32.0% to 37.6% (p = 0.005) and from 2.0% to 3.3% (p = 0.022), respectively. The use of CT rose from 67.2% to 88.8% (p < 0.001) and that of MRI from 5.0% to 35.2% (p < 0.001). The proportion of patients suffering from complications decreased from 7.9% to 5.3% (p < 0.001) for intraoperative and from 28.0% to 18.6% (p < 0.001) for postoperative surgical complications, but general postoperative complications increased from 25.8% to 29.5% (p = 0.006). The distribution of histopathological stage, anastomotic leakage, and in-hospital mortality did not change significantly. CONCLUSION: Participation in a quality assurance project improves compliance with treatment standards, especially for diagnostic procedures. An improvement of surgical results will require further investment in training.

Treatment and Survival of Patients with Colon Cancer Aged 80 Years and Older: A EURECCA International Comparison.

BACKGROUND: Colon cancer in older patients represents a major public health issue. As older patients are hardly included in clinical trials, the optimal treatment of these patients remains unclear. The present international EURECCA comparison explores possible associations between treatment and survival outcomes in elderly colon cancer patients. SUBJECTS, MATERIALS, AND METHODS: National data from Belgium, Denmark, The Netherlands, Norway, and Sweden were obtained, as well as a multicenter surgery cohort from Germany. Patients aged 80 years and older, diagnosed with colon cancer between 2001 and 2010, were included. The study interval was divided into two periods: 2001-2006 and 2007-2010. The proportion of surgical treatment and chemotherapy within a country and its relation to relative survival were calculated for each time frame. RESULTS: Overall, 50,761 patients were included. At least 94% of patients with stage II and III colon cancer underwent surgical removal of the tumor. For stage II-IV, the proportion of chemotherapy after surgery was highest in Belgium and lowest in The Netherlands and Norway. For stage III, it varied from 24.8% in Belgium and 3.9% in Norway. For stage III, a better adjusted relative survival between 2007 and 2010 was observed in Sweden (adjusted relative excess risk [RER] 0.64, 95% confidence interval [CI]: 0.54-0.76) and Norway (adjusted RER 0.81, 95% CI: 0.69-0.96) compared with Belgium. CONCLUSION: There is substantial variation in the rate of treatment and survival between countries for patients with colon cancer aged 80 years or older. Despite higher prescription of adjuvant chemotherapy, poorer survival outcomes were observed in Belgium. No clear linear pattern between the proportion of chemotherapy and better adjusted relative survival was observed. IMPLICATIONS FOR PRACTICE: With the increasing growth of the older population, clinicians will be treating an increasing number of older patients diagnosed with colon cancer. No clear linear pattern between adjuvant chemotherapy and better adjusted relative survival was observed. Future studies should also include data on surgical quality.

Risk factors, short and long term outcome of anastomotic leaks in rectal cancer.

BACKGROUND: An anastomotic leak (AL) after colorectal surgery is one major reason for postoperative morbidity and mortality. There is growing evidence that AL affects short and long term outcome. This prospective German multicentre study aims to identify risk factors for AL and quantify effects on short and long term course after rectal cancer surgery. METHODS: From 1 January 2000 to 31 December 2010 381 hospitals attributed patients to the prospective multicentre study Quality Assurance in Colorectal Cancer managed by the Otto-von-Guericke-University Magdeburg (Germany). Included were 17 867 patients with histopathologically confirmed rectal carcinoma and primary anastomosis. Risk factor analysis included 13 items of demographic patient data, surgical course, hospital volume und tumour stage. RESULTS: In 2 134 (11.9%) patients an AL was diagnosed. Overall hospital mortality was 2.1% (with AL 7.5%, without AL 1.4%; p < 0.0001). In multivariate analysis male gender, ASA-classification ≥III, smoking history, alcohol history, intraoperative blood transfusion, no protective ileostomy, UICC-stage and height of tumour were independent risk factors. Overall survival (OS) was significantly shorter for patients with AL (UICC I-III; UICC I, II or III - each p < 0.0001). Disease free survival (DFS) was significantly shorter for patients with AL in UICC I-III; UICC II or UICC III (each p < 0.001). Rate of local relapse was not significantly affected by occurrence of AL. CONCLUSIONS: In this study patients with AL had a significantly worse OS. This was mainly due to an increased in hospital mortality. DFS was also negatively affected by AL whereas local relapse was not. This emphasizes the importance of successful treatment of AL related problems during the initial hospital stay.

German Bowel Cancer Center: An Attempt to Improve Treatment Quality.

Background. Colorectal cancer remains the second most common cause of death from malignancies, but treatment results show high diversity. Certified bowel cancer centres (BCC) are the basis of a German project for improvement of treatment. The aim of this study was to analyze if certification would enhance short-term outcome in rectal cancer surgery. Material and Methods. This quality assurance study included 8197 patients with rectal cancer treated between 1 January 2008 and 31 December 2010. We compared cohorts treated in certified and noncertified hospitals regarding preoperative variables and perioperative outcomes. Outcomes were verified by matched-pair analysis. Results. Patients of noncertified hospitals had higher ASA-scores, higher prevalence of risk factors, more distant metastases, lower tumour localization, lower frequency of pelvic MRI, and higher frequencies of missing values and undetermined TNM classifications (significant differences only). Outcome analysis revealed more general complications in certified hospitals (20.3% versus 17.4%, p = 0.03). Both cohorts did not differ significantly in percentage of R0-resections, intraoperative complications, anastomotic leakage, in-hospital death, and abdominal wall dehiscence. Conclusions. The concept of BCC is a step towards improving the structural and procedural quality. This is a good basis for improving outcome quality but cannot replace it. For a primary surgical disease like rectal cancer a specific, surgery-targeted program is still needed.

Nosocomial Infections and Microbiologic Spectrum after Major Elective Surgery of the Pancreas, Liver, Stomach, and Esophagus.

BACKGROUND: The majority of infections treated by surgeons are nosocomial infections (NI). The frequency of these infections in relation to the organ operated on as well as the organisms involved are not well defined. Detailed knowledge of these issues is essential for optimal care of surgical patients. This study aimed to determine infection rates and the responsible pathogens after major elective surgery of the pancreas, liver, stomach, and esophagus. METHODS: Between January 1, 2005 and August 31, 2007, the records of all patients of the Department of General, Abdominal and Vascular Surgery, University Hospital Magdeburg (Germany) with elective resection of the pancreas, liver, stomach, and esophagus were evaluated retrospectively. Study parameters were: Patient number, age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, indication for resection, operation duration, length of stay (LOS) in the intensive care unit (ICU) and in hospital, mortality, organ-related rate and kind of NI, and microbiologic spectrum. Nosocomial infections were defined as: Surgical site infection (U.S. Centers for Disease Control and Prevention [CDC] 1 or 2) and intra-abdominal infection (CDC 3), urinary tract infection, clinical sepsis, blood stream and catheter-related infection, respiratory tract infection, and pneumonia. RESULTS: A total of 358 patients were included: 150 (42%) with pancreas resection, 91 (25%) with liver resection, 105 (29%) with gastric resection, and 12 (3%) with esophagus resection. Median LOS in the ICU for all groups was 48.8 h (interquartile range [IQR] 24.9-91.8 h), median LOS in hospital was 16 d (IQR 13-23 d), and in-hospital mortality was 4.5%. Patients with NI had significantly greater in-hospital death and prolonged stay in hospital and ICU (p<0.001). In 120 (33.5%) patients, one or more NI occurred (range, 83% in esophagus patients to 21% in liver patients). Intra-abdominal (16.5%) and surgical site infections (12.3%) were most frequent; 80.8% of the NI were culture-positive. The most frequent clinically relevant isolates were Escherichia coli (12.4%), coagulase-negative staphylococci (CoNS) (12.2%), and Enterococcus faecium (9.7%). The highest resistance rates were found for Staphylococcus aureus (methicillin-resistant S. aureus [MRSA] 29.4%) and Pseudomonas aeruginosa (23.5%). CONCLUSIONS: For patients undergoing elective surgery of the pancreas, liver, stomach, and esophagus, considerable differences in demographic factors, frequency, and kind of NI exist. The consequences of NI force surgeons to analyze pre-operative risk factors carefully, assess indications for operation thoroughly, and optimize all controllable parameters.