Deep learning identifies inflamed fat as a risk factor for lymph node metastasis in early colorectal cancer.

The spread of early-stage (T1 and T2) adenocarcinomas to locoregional lymph nodes is a key event in disease progression of colorectal cancer (CRC). The cellular mechanisms behind this event are not completely understood and existing predictive biomarkers are imperfect. Here, we used an end-to-end deep learning algorithm to identify risk factors for lymph node metastasis (LNM) status in digitized histopathology slides of the primary CRC and its surrounding tissue. In two large population-based cohorts, we show that this system can predict the presence of more than one LNM in pT2 CRC patients with an area under the receiver operating curve (AUROC) of 0.733 (0.67-0.758) and patients with any LNM with an AUROC of 0.711 (0.597-0.797). Similarly, in pT1 CRC patients, the presence of more than one LNM or any LNM was predictable with an AUROC of 0.733 (0.644-0.778) and 0.567 (0.542-0.597), respectively. Based on these findings, we used the deep learning system to guide human pathology experts towards highly predictive regions for LNM in the whole slide images. This hybrid human observer and deep learning approach identified inflamed adipose tissue as the highest predictive feature for LNM presence. Our study is a first proof of concept that artificial intelligence (AI) systems may be able to discover potentially new biological mechanisms in cancer progression. Our deep learning algorithm is publicly available and can be used for biomarker discovery in any disease setting. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Combined endoscopic and laparoscopic surgery (CELS) for early colon cancer in high-risk patients.

BACKGROUND: Local excision of early colon cancers could be an option in selected patients with high risk of complications and no sign of lymph node metastasis (LNM). The primary aim was to assess feasibility in high-risk patients with early colon cancer treated with Combined Endoscopic and Laparoscopic Surgery (CELS). METHODS: A non-randomized prospective feasibility study including 25 patients with Performance Status score ≥ 1 and/or American Society of Anesthesiologists score ≥ 3, and clinical Union of International Cancer Control stage-1 colon cancer suitable for CELS resection. The primary outcome was failure of CELS resection, defined as either: Incomplete resection (R1/R2), local recurrence within 3 months, complication related to CELS within 30 days (Clavien-Dindo grade ≥ 3), death within 30 days or death within 90 days due to complications to surgery. RESULTS: Fifteen patients with clinical T1 (cT1) and ten with clinical T2 (cT2) colon cancer and without suspicion of metastases were included. Failure occurred in two patients due to incomplete resections. Histopathological examination classified seven patients as having pT1, nine as pT2, six as pT3 adenocarcinomas, and three as non-invasive tumors. In three patients, the surgical strategy was changed intraoperatively to conventional colectomy due to tumor location or size. Median length of stay was 1 day. Seven patients had completion colectomy performed due to histological high-risk factors. None had LNM. CONCLUSIONS: In selected patients, CELS resection was feasible, and could spare some patients large bowel resection.

The topographical distribution of lymph node metastases in colon cancer resections.

In accordance with international guidelines all lymph nodes in colon cancer specimens must be examined to obtain accurate staging. This study aimed to determine the topographical location of lymph node metastases and evaluate if a more limited sampling approach could be an alternative. Partial colectomies received at the Department of Pathology, Zealand University Hospital during a six-month period were included. At the macroscopic examination, each specimen was divided into three different segments: a segment containing the index tumor and the tumor-feeding artery, an oral and an anal segment. The number of lymph nodes and lymph node metastases were registered separately for each segment. Resections from 93 patients were included. Of 2466 lymph nodes, 1839 (74.6 %) were located in the tumor segment, 308 (12.5 %) in the oral, and 319 (12.9 %) in the anal segment, respectively. In 133 (5,4 %) lymph nodes a metastasis was present. Of these 129 (97.0 %) were located in the tumor segment, one (0.8 %) in the oral segment, and three (2.3 %) in the anal segment. No patients had metastasis in the oral or anal segments without metastases also being present in the tumor segment leading to consideration of the need for lymph node harvest of the complete specimen upon initial examination. As such, the segment containing the index tumor and tumor-feeding artery could be regarded as a sentinel segment indicating a potential need for lymph node dissection in the oral and anal segments.

An exploration of immunohistochemistry-based prognostic markers in patients undergoing curative resections for colon cancer.

BACKGROUND: The immune system recognizes and destroys cancer cells. However, cancer cells develop mechanisms to avoid detection by expressing cell surface proteins. Specific tumour cell surface proteins (e.g. HLA-G, PD-L1, CDX2) either alone or in combination with the relative presence of immune cells (CD3 and CD8 positive T-cells) in the tumour tissue may describe the cancer cells' ability to escape eradication by the immune system. The aim was to investigate the prognostic value of immunohistochemical markers in patients with colon cancer. METHODS: We conducted a retrospective study including patients diagnosed with pT3 and pT4 colon cancers. Immunohistochemical staining with HLA-G, PD-L1, CDX2, CD3, and CD8 was performed on tissue samples with representation of the invasive margin. PD-L1 expression in tumour cells and immune cells was reported conjointly. The expression of CD3 and CD8 was reported as a merged score based on the expression of both markers in the invasive margin and the tumour centre. Subsequently, a combined marker score was established based on all of the markers. Each marker added one point to the score when unfavourable immunohistochemical features was present, and the score was categorized as low, intermediate or high depending on the number of unfavourable stains. Hazard ratios for recurrence, disease-free survival and mortality were calculated. RESULTS: We included 188 patients undergoing colon cancer resections in 2011-2012. The median follow-up was 41.7 months, during which 41 (21.8%) patients had recurrence and 74 (39.4%) died. In multivariable regression analysis positive HLA-G expression (HR = 3.37, 95%CI [1.64-6.93]) was associated with higher recurrence rates, while a preserved CDX2 expression (HR = 0.23, 95%CI [0.06-0.85]) was associated with a lower risk of recurrence. An intermediate or high combined marker score was associated with increased recurrence rates (HR = 20.53, 95%CI [2.68-157.32] and HR = 7.56, 95%CI [1.06-54.16], respectively). Neither high expression of PD-L1 nor high CD3-CD8 score was significantly associated with recurrence rates. Patients with a high CD3-CD8 score had a significantly longer DFS and OS. CONCLUSIONS: In tumour cells, expression of HLA-G and loss of CDX2 expression were associated with cancer recurrence. In addition, a combination of certain tumour tissue biomarkers was associated with colorectal cancer recurrence.

Perioperative changes in cell-free DNA for patients undergoing surgery for colon cancer.

BACKGROUND: Various conditions with cellular decay are associated with elevated cell-free DNA (cfDNA). This study aimed to investigate if perioperatively measured cfDNA levels were associated with the surgical approach, complications, or recurrence. METHODS: Plasma was obtained from patients who underwent surgery for colon cancer at admission and at the time of discharge. Quantitative measurement of cfDNA was performed by amplifying two amplicons of 102 base pairs (bp) and 132 bp of Beta-2-Microglobulin (B2M) and Peptidyl-Prolyl cis-trans Isomerase A (PPIA), respectively. RESULTS: cfDNA was measured in 48 patients who underwent surgery for colonic cancer. Sixteen patients had recurrence during the follow-up period, fifteen developed a postoperative complication, and seventeen patients developed neither, acting as the control group. Postoperative cfDNA levels were significantly elevated from baseline samples, across all groups, with a median preoperatively B2M level of 48.3 alleles per mL and postoperatively of 220 alleles per mL and a median preoperatively level PPIA of 26.9 alleles per mL and postoperatively of 111.6 alleles per mL (p < 0.001 for B2M and p < 0.001 for PPIA). Postoperative levels of PPIA, but not B2M, were significantly higher in patients experiencing complications than in the control group (p = 0.036). However, a tendency towards an association between the surgical approach and the changes in cfDNA levels was found for PPIA (p = 0.058), and B2M (p = 0.087). CONCLUSIONS: Plasma cfDNA was increased after surgery in all patients with colon cancer. Postoperative PPIA levels were significantly higher in patients experiencing surgical complications but not in B2M levels.

In vivo and ex vivo sentinel node mapping does not identify the same lymph nodes in colon cancer.

INTRODUCTION: Identification of lymph nodes and pathological analysis is crucial for the correct staging of colon cancer. Lymph nodes that drain directly from the tumor area are called "sentinel nodes" and are believed to be the first place for metastasis. The purpose of this study was to perform sentinel node mapping in vivo with indocyanine green and ex vivo with methylene blue in order to evaluate if the sentinel lymph nodes can be identified by both techniques. METHODS: Patients with colon cancer UICC stage I-III were included from two institutions in Denmark from February 2015 to January 2016. In vivo sentinel node mapping with indocyanine green during laparoscopy and ex vivo sentinel node mapping with methylene blue were performed in all patients. RESULTS: Twenty-nine patients were included. The in vivo sentinel node mapping was successful in 19 cases, and ex vivo sentinel node mapping was successful in 13 cases. In seven cases, no sentinel nodes were identified. A total of 51 sentinel nodes were identified, only one of these where identified by both techniques (2.0%). In vivo sentinel node mapping identified 32 sentinel nodes, while 20 sentinel nodes were identified by ex vivo sentinel node mapping. Lymph node metastases were found in 10 patients, and only two had metastases in a sentinel node. CONCLUSION: Placing a deposit in relation to the tumor by indocyanine green in vivo or of methylene blue ex vivo could only identify sentinel lymph nodes in a small group of patients.

Detection of collision metastases.

Cancer is a cause of high morbidity and mortality. It is not uncommon for a patient to have more than one primary tumour. This review summarises the knowledge of collision tumours which are defined as two adjacent neoplasms in the same organ, while a collision metastasis is the rare occurrence of two different primary cancers metastasising to the same anatomical site. Identification of collision metastasis is a diagnostic challenge and relies on histopathological examination. As it might have profound impact on prognosis and treatment decisions, it is important to create awareness among both pathologists and clinicians of this phenomenon.

Deeper sections reveal residual tumor cells in rectal cancer specimens diagnosed with pathological complete response following neoadjuvant treatment.

Guidelines and requirements for diagnosing pathological complete response (pCR) in rectal adenocarcinoma following neoadjuvant treatment vary, and there is currently no consensus on the appropriate number of sections to examine per formalin-fixed, paraffin-embedded (FFPE) tissue block. The consequences of systematic use of deeper sections on the diagnostic accuracy and prognosis for patients classified as ypT0 rectal cancer were investigated. In this retrospective study, 23 out of 155 patients who underwent neoadjuvant therapy and surgical resection between 2015 and 2020 were diagnosed with ypT0 rectal cancer. Three additional deeper sections were cut from each FFPE block from the primary tumor site and reviewed for presence of residual tumor cells. Additional sections revealed residual viable tumor cells in seven patients (30.4%), reducing the rate of pCR in the cohort from 14.8 to 10.3%. Of the seven patients, three patients later had local recurrence or distant metastasis during the follow-up period, compared with one patient with no residual tumor cells in deeper sections (p = 0.07). A nonsignificant reduction in disease-free survival (p = 0.08) was observed in the patients with residual tumor. Systematic use of deeper sections in evaluation of tumor regression in rectal cancer reveals the presence of residual tumor cells in a subset of patients originally diagnosed with pCR based on a single section per FFPE block. Although the results are not statistically significant, it cannot be excluded that accurately distinguishing complete from near-complete response may be clinically relevant for prognostic prediction.

Total mesocolic excision versus traditional resection in right-sided colon cancer - method and increased lymph node harvest.

INTRODUCTION: Rectal surgery has followed a steady trend towards improved surgical techniques over the past 15 years. Danish colon cancer surgery has not witnessed similar progress. Hohenberger described a comprehensive method involving complete excision of all mesocolic tissue which is equivalent to right-sided hemicolectomy. The present work describes the difference between the traditional surgical method and the comprehensive method, and provides detail on the outcome in 11 patients with regard to morbidity, mortality and lymph node status. MATERIAL AND METHODS: Eleven cases with tumours located orally to the right flexure were included in the study. Surgery was performed using the comprehensive method. After excision of the specimen, the surgeon determined and marked-up the extra central part of the mesentery which had been excised. A pathologist examined the specimen. The extra mesentery segment was independently examined, described and embedded for microscopy, mortality rate, major adverse cardiovascular events, symptom relief and quality-of-life at six-month follow-up. RESULTS: Lymph nodes were found in the extra segment of all specimens, and in two patients the extra segment contained malignant lymph nodes. We found twelve or more lymph nodes in all specimens. Without the extra specimen segment, this would not have been possible in five of the patients. CONCLUSION: Our finding of centrally located lymph nodes confirms Hohenberger's claim that the probability of successful macro-radical removal increases with the removal of such lymph nodes, and removal of as many lymph nodes as possible should generally be considered beneficial to the patient.

Impact of in Vivo Ischemic Time on RNA Quality--Experiences from a Colon Cancer Biobank.

Considerable effort has been made to improve differentiated diagnostics as well as personalized treatment for colorectal cancer patients. High-quality fresh frozen tissue is often required to investigate relevant molecular signatures in these patients. In RNA expression studies, the "RNA integrity number" is widely accepted as a reliable marker of RNA quality. Here, we investigate the feasibility of obtaining high-quality tissue from a colon cancer biobank and the impact of in vivo ischemic time and various technical and clinicopathological factors on RNA quality. Biopsies were obtained immediately following the tumor removal. The time from clamping the main arterial supply to resection and removal of the tumor was used to estimate the in vivo ischemic time. We did not observe a significant difference in RNA quality between normal tissue and tumor tissue. We observed a significant correlation between in vivo ischemic time and RNA quality in normal tissue (r = -0.24, p<0.001) but not in tumor tissue. Male gender and laparoscopic procedure were also significantly associated with lower RNA quality in normal tissue only. In tumor tissue, poor differentiation was associated with low RNA quality. In conclusion, in vivo ischemic time, surgical procedure, and gender have minor but significant effects on the quality of RNA from normal colon tissue but not tumor tissue. Poorly differentiated tumors are associated with lower RNA quality. Although its impact is low, it can still be considered to note in vivo ischemic time in colon cancer specimen procurement.

High interleukin-6 mRNA expression is a predictor of relapse in colon cancer.

AIM: To investigate the expression of interleukin-6 (IL6) in colon cancer tissue, and to examine if the risk of relapse is influenced by IL6 expression. MATERIALS AND METHODS: Fresh-frozen biopsies from tumor and normal adjacent tissues were taken from patients with colon cancer during surgery and stored at -80 °C. mRNA expression for interleukin-6 was evaluated with reverse transcription real time quantitative polymerase chain reaction. Survival analyses were carried-out using a Cox competing risk regression model. RESULTS: IL6 mRNA was significantly more highly expressed in tumor tissue compared to normal adjacent tissue (p<0.001). We found no significant association with regard to IL6 expression and histological differentiation or cancer stage. We found a significant association between high IL6 expression and risk of relapse (Hazard Ratio=2.23, 95% CI=1.10-4.53; p<0.05), also when adjusted for clinicopathological characteristics (Hazard Ratio=2.16, 95% CI=1.07-4.40; p<0.05). CONCLUSION: Interleukin-6 is up-regulated in colon cancer tissue at the transcriptional level and is significantly associated with increased risk of relapse.

[The first case of cap polyposis in Denmark].

Cap polyposis (CP) is characterized by the presence of inflammatory polyps mainly involving the rectosigmoid. It primarily causes mucous to bloody diarrhoea and is often misdiagnosed initially. We report the first case in Denmark with multiple polyps in the rectosigmoid causing constipation in between periods of mucous and bloody diarrhoea. He was initially misdiagnosed as having ulcerative colitis with pseudopolyps. Due to insufficient effect of medical treatment biopsies from the polyps were obtained. They showed typical histological signs of CP. He was successfully treated by rectosigmoid resection.

[Not all dietary supplements are biodegradable]. / Ikke alle kosttilskud er biologisk nedbrydelige

A 65-year-old man had for some time noticed rounded elements in his faeces. It was examined for parasites, which were, however, not detected. A specimen was then sent to a department of pathology. The specimen consisted of a rounded and collapsed process, 12 mm in diameter. It was quite thin-walled and hollow; the wall itself was tough and not elastic and classified as non-biological material. It was concluded that it was probably a capsule of medicine, dietary supplements, oil or a similar substance. The patient had eaten fish oil in capsules, and they had apparently not been biodegradable.

Endoscopic brush cytology from the biliary duct system is still valuable.

INTRODUCTION: The aim of this study was to define sensitivity, specificity and positive and negative predictive values of endoscopic retrograde cholangiopancreatography (ERCP) brush cytology from biliary strictures obtained over a period of 12 years in a county hospital in Denmark. MATERIAL AND METHODS: Patients with cytology specimens identified by brushings of the bile duct, pancreatic duct and ampulla of Vater were included. The specimens were reported as unsatisfactory, normal, atypical, suspicious for malignancy or malignant. Our evaluation comprised 75 specimens. For the statistical analysis, an atypical cytology result was considered benign, and a suspicious result was considered malignant. The cytological diagnoses were compared with the final diagnoses which were established either by histopathology (surgery, biopsy or autopsy) or by at least one year of clinical follow-up. RESULTS: Of the 75 specimens included, 40 were diagnosed as cytologically benign (35 normal and five atypical) and 35 as cytologically malignant (22 suspicious for malignancy and 13 malignant). Comparing the cytological diagnosis with the final diagnosis, we found 35 to be true positives, 22 to be true negatives, zero to be false positives and 18 to be false negatives. Of the five atypical specimens, four were false negatives. The operating characteristics were: 66% sensitivity, 100% specificity, 100% positive predictive value and 55% negative predictive value. The diagnostic accuracy was 76%. CONCLUSION: Suspicion and malignant cytology are reliable with a specificity of 100%. In these cases, we recommend that the patients are considered for surgical or oncological treatment without further histological investigations. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

[Caecal diverticulitis in a young woman with suspected acute appendicitis]. / Cækal divertikulitis hos en ung kvinde med formodet appendicitis acuta

Colonic diverticular disease is common amongst the western population in the left hemicolon while right-sided involvement is rare. This case concerns a 20-year-old female, who was hospitalized with suspected acute appendicitis. Perioperative findings included an intramural tumour at the base of the appendix, and an ileocaecal resection was performed. Histopathological examinations revealed a single inflamed diverticulum of the caecum. The case illustrates the pre- and perioperatively differential diagnostic problems of caecal diverticulitis, which can lead to more radical surgery than needed.

[Pilonidal disease is a benign condition]. / Pilonidalsygdom er en benign lidelse.

Malignant transformation in pilonidal disease is rare and never reported in Denmark. There are 75 cases in the literature, mostly squamous cell carcinoma. The cost-benefit of routine histological examination of specimens from pilonidal surgery is questionable, as malignancy is extremely rare. Due to increased incidence of cancer, specimens from patients with many years of pilonidal disease, known immunodeficiencies and/or human papillomavirus infection or clinical abnormal presentation, should always be investigated.

[Sarcomatoid mesothelioma--a diagnostic challenge]. / Sarkomatoidt mesoteliom--en diagnostisk udfordring.

This is the case of a 62-year-old carpenter in whom a computed tomography showed a widespread "mesothelioma-like" tumour of the pleura. Needle biopsy and later autopsy showed malignant sarcomatoid tumour. The tumour stained negatively for calretinin and other "mesothelial markers". Diagnosis has important legal implications for the relatives, we therefore find it important to stress that sarcomatoid mesothelioma is usually calretinin-negative.

[Intestinal tuberculosis as a differential diagnosis of inflammatory bowel disease]. / Intestinal tuberkulose som differentialdiagnose til inflammatorisk tarmsygdom.

Intestinal tuberculosis (ITB) is a rare differential diagnosis of inflammatory bowel disease (IBD) in Denmark. In the presented case, a 44-year-old native Danish man was examined for IBD symptoms. Colonoscopy and microscopy of colonic biopsies suggested IBD. The patient was started on steroid therapy, but without effect so tumour necrosis factor alpha therapy was planned. Routine interferon-gamma release assay was normal, but chest X-ray revealed an apical infiltration. New tests on the colonic biopsies using polymerase chain reaction were positive for Mycobacterium tuberculosis and the patient was treated for ITB and pulmonary tuberculosis.

[Epithelioid trophoblastic tumour]. / Epiteloid trofoblasttumor.

Epithelioid trophoblastic tumour is a rare gestational trophoblastic disease. The diagnosis is based on microscopic morphology and immunohistochemical staining. It is important to avoid misdiagnosis, as this tumour is primarily treated by surgery rather than chemotherapy. We report a case and describe diagnostic criteria and differential diagnoses.

[Rhabdomyoma in the head and neck region]. / Rabdomyom i hoved-hals-regionen.

Extracardiac rhabdomyoma is an extremely uncommon benign neoplasm with skeletal muscle differentiation which usually involves the head and neck region. We report two cases of extracardiac adult rhabdomyoma affecting adult patients and initially seen as slowly-growing, indolent neoplasms. In both cases, an asymptomatic neck mass was noticed by the patient. Complete local excision without radical surgery was performed and histological findings confirmed the diagnosis of adult rhabdomyoma. Adult rhabdomyomas should be considered as a differential diagnosis in the head and neck region.