PAIP 2020: Microsatellite instability prediction in colorectal cancer.

Microsatellite instability (MSI) refers to alterations in the length of simple repetitive genomic sequences. MSI status serves as a prognostic and predictive factor in colorectal cancer. The MSI-high status is a good prognostic factor in stage II/III cancer, and predicts a lack of benefit to adjuvant fluorouracil chemotherapy in stage II cancer but a good response to immunotherapy in stage IV cancer. Therefore, determining MSI status in patients with colorectal cancer is important for identifying the appropriate treatment protocol. In the Pathology Artificial Intelligence Platform (PAIP) 2020 challenge, artificial intelligence researchers were invited to predict MSI status based on colorectal cancer slide images. Participants were required to perform two tasks. The primary task was to classify a given slide image as belonging to either the MSI-high or the microsatellite-stable group. The second task was tumor area segmentation to avoid ties with the main task. A total of 210 of the 495 participants enrolled in the challenge downloaded the images, and 23 teams submitted their final results. Seven teams from the top 10 participants agreed to disclose their algorithms, most of which were convolutional neural network-based deep learning models, such as EfficientNet and UNet. The top-ranked system achieved the highest F1 score (0.9231). This paper summarizes the various methods used in the PAIP 2020 challenge. This paper supports the effectiveness of digital pathology for identifying the relationship between colorectal cancer and the MSI characteristics.

A Minimum Ten Years of Follow-Up of Alumina Head on Delta Liner Total Hip Arthroplasty.

BACKGROUND: In the early days when delta ceramics were developed, there was a period of using delta ceramic liner and alumina ceramic head. Therefore, the purpose of this study is to investigate the clinical and radiological outcomes of total hip arthroplasty using delta ceramic liner on alumina ceramic head after a minimum of 10 years of follow-up and to evaluate problems of early delta ceramic liner. METHODS: Alumina on delta cementless total hip arthroplasty was performed in 92 hips (85 patients) from August 2005 to March 2007 at our hospital. Bilateral total hip arthroplasty were performed in 7 patients, 30 patients on the left side and 48 patients on the right side. Preoperative diagnosis was osteonecrosis of the femoral head in 34 hips (37%), degenerative arthritis in 31 hips (33.7%), femur neck fracture in 21 hips (22.8%), and rheumatoid arthritis in 6 hips (6.5%). All surgeries were carried out with anterolateral approach. For the clinical evaluation, Harris hip score (HHS), pain, and range of motion were assessed. Radiographs were reviewed by the authors to search for any signs of osteolysis, loosening of implants, and heterotopic ossification. RESULTS: HHS was compared between preoperative and final follow-ups. The mean HHS improved from preoperative 58.3 points (range 27-76) to 92.7 points (range 78-98) on the final follow-up (P = .02). The mean range of hip motion at the final follow-up was flexion 116.9°, adduction 23.8°, abduction 34.6°, internal rotation 16.3°, and external rotation 39.2°. As for the postoperative pain, 1 patient complained of inguinal pain and 4 patients complained of thigh pain. Because of trauma, 3 cases of dislocation were observed in all cases. There are 3 cases with dislocation and 2 cases were treated with conservative treatment without recurrence, but 1 case was required for surgical treatment due to eccentric rim wear of delta liner. The aseptic loosening of acetabular cup and femoral stem was each 1 hip. CONCLUSION: Alumina head-on-delta liner cementless THA, using a large femoral head 32-36 mm in diameter, demonstrated satisfactory clinical and radiological results in the minimum 10 years of follow-up. Eccentric rim wear can occur even in delta ceramic liners that are known to have high strength, and this can lead to dislocation which can, in turn, increase the possibility of linear fracture.

Clinical impact of K-ras mutation in colorectal cancer patients treated with adjuvant FOLFOX.

BACKGROUND: K-ras proto-oncogene is commonly mutated in colorectal cancer (CRC) and has been associated with predictive markers for anti-EGFR (epidermal growth factor receptor) therapy. However, the prognostic role of K-ras status is still unclear. The aim of this study was to evaluate the association between k-ras status and addition of oxaliplatin to fluorouracil plus leucovorin (FOLFOX) chemotherapy in CRC patients with curative surgical resection. METHODS: Sixty-six patients with stage II or III CRC were treated with FOLFOX or fluorouracil plus leucovorin (FL) followed by curative surgery between January 2004 and October 2007. K-ras status was assessed by direct sequencing. RESULTS: Fifteen patients (22.7%) had K-ras mutations of codon 12 (11/15) or codon 13 (4/15). There were no significant differences in clinicopathological parameters, such as age, sex, stage, or adjuvant regimen between the wild-type K-ras and mutant K-ras. With a median follow-up of 41.6 months (range 25.1-72.3 months), median disease-free survival (DFS) and overall survival (OS) were not reached. With regard to K-ras status, DFS and OS were not statistically different (P = 0.269 and P = 0.917, respectively). Even in the group treated with FOLFOX only, neither DFS (P = 0.651) nor OS (P = 0.265) was significantly different according to K-ras status. With the exception of tumor location in DFS and OS, no differences in other variables were observed. Proximal colon cancer patients had a longer DFS than distal CRC patients (P = 0.079); this trend was maintained only in the wild-type K-ras group (P = 0.051). CONCLUSIONS: These results showed that K-ras status was not associated with clinical outcome in patients treated with adjuvant FOLFOX.