Differences in colorectal cancer between China and Japan: a clinical and histological study of two groups of cases

The pathological behaviors and prognostic factors of Chinese and Japanese colorectal cancers from general hospitals: a comparative study of the inpatients with surgical operation

Here, we collected the information of 17304 and 2014 inpatients with colorectal cancer (CRC) from general hospitals of China and Japan respectively, and analyzed microscopic and macroscopic aspects, even stratified by the age and gender. It was found that Chinese CRC patients showed younger prone, more rectal and ascending cancers, less sigmoid and transverse cancers, larger size, less invasion into lymphatic system or metastasis into lymph node, and poorer differentiation than Japanese ones (p < 0.05). TNM staging was employed as an independent factor for the prognosis of the CRC patients regardless of the country (p < 0.05). Female patients showed larger tumor size, easier invasion and metastasis into lymphatic system, and worse differentiation than males (p < 0.05). The younger patients displayed frequent invasion and metastasis into lymphatic system, and poor differentiation in comparison to elder ones (p < 0.05). These findings demonstrated that Japanese patients seemed to have more invasion and metastasis due to standard and precise operation and pathological diagnosis accuracy. Actually, Chinese patients had more aggressive pathological characteristics and a poorer prognosis. Therefore, it is essential to establish a routine screening methodology, a standard treatment system and postoperative diagnosis protocol for the prevention and therapeutics of Chinese CRC patients, especially for female and young patients.

Ulcerative colitis-associated colorectal cancer shows a poorer survival than sporadic colorectal cancer: a nationwide Japanese study

BACKGROUND

The clinicopathological features of ulcerative colitis-associated colorectal cancer (UC-CRC) have not yet been fully clarified, especially in Asian populations. This study aimed to clarify the prognosis and clinicopathological features of UC-CRC in comparison with sporadic CRC in the Japanese population.

METHODS

Histologically diagnosed UC-CRC patients between 1978 to 1998 were extracted from the Multi-Institutional Registry of Large-Bowel Cancer in Japan, a large nationwide CRC database, and the clinicopathological features and postoperative survival rates of UC-CRC patients and sporadic CRC patients were compared.

RESULTS

Among the 108,536 CRC patients registered between 1978 and 1998, a total of 169 UC-CRC patients were identified, including 121 patients who had been treated surgically. The proportion of UC-CRC patients increased in the period between 1995 and 1998 compared to that between 1978 and 1994. Comparisons with the sporadic CRC patients showed that the UC-CRC patients were younger, had a higher proportion of multiple cancer lesions, had higher proportions of superficial type lesions and invasive type lesions morphologically, and had higher proportions of mucinous or signet ring cell carcinomas. In stage III, UC-CRC patients had a poorer survival rate than the sporadic CRC patients (43.3% versus 57.4%, P = 0.0320).

CONCLUSIONS

UC-CRC increased over the investigated time periods and showed a poorer survival than sporadic CRC in the advanced stage, while no difference was observed in the early stage. By detecting UC-CRC at an early stage we can expect a similar postoperative outcomes to that of sporadic CRC. These results stress the importance of surveillance for the early detection of UC-CRC.

Establishment and characterization of 13 human colorectal carcinoma cell lines: mutations of genes and expressions of drug-sensitivity genes and cancer stem cell markers

Thirteen human colorectal cancer (CRC) cell lines were established from 10 primary tumors and 3 metastatic tumors obtained from 13 Korean patients. Characteristics of the cell lines including morphology in vivo and in vitro; mutations of the K-ras, p53, APC and MMR genes and microsatellite instability (MSI) status in vitro were determined. Expression of drug-sensitivity genes including MDR1, MXR, MRP1 and COX2 was also analyzed. The cell lines were unique as judged by DNA fingerprinting using 16 short tandem repeats. Eleven of the cell lines grew as adherent populations and the remaining two as floating aggregates. None of the cell lines were contaminated with Mycoplasma or bacteria. All cell lines showed high viability with relatively long doubling times. Six cell lines contained mutations at K-ras. Seven cell lines displayed p53 gene missense, nonsense and frameshift mutations. MSI was found in three cell lines and two cell lines with an MSI-high phenotype-possessed hMLH1 mutations. Nine cell lines had an APC mutation. MRP1 was highly expressed in all cell lines, and high expression of MDR1, MXR and COX2 evident in eight, six and six cell lines, respectively. Embryonal stem cell markers (MELK, SOX4 and OCT4) were expressed in most of cell lines. The cancer stem cell biomarkers CD133, CD44 and Lgr5 were expressed in 12, 13 and 13 cell lines, respectively. The presently well-characterized CRC cell lines should be useful in investigations of the biological characteristics of CRC, particularly for investigations related to gene alterations associated with CRC and biology of cancer stem cells.

Isolation and characterization of two novel colon cancer cell lines from Chinese patients

Incidence of colon cancer has increased rapidly in China. Although many colon cancer cell lines have been established previously, most of them were derived from patients from western countries. Epidemiological, clinical, cytogenetic, and molecular biological studies showed that there are considerable differences between Chinese and western countries colon cancer patients. Therefore, establishment of novel colon cancer cell line from Chinese is useful for studying the racial difference of this disease and can be important for studying the pathogenesis of colon cancer in China. In our laboratory, two novel continuous human colon cancer cell lines, SHT-1 and SHH-1, have been established in vitro from Chinese patients, and both cell lines have been passaged for 4 yr, and they have been continuously subcultured with more than 800 population doubling and without signs of senescence. Both cell lines were obtained from primary tumor tissues during colon cancer surgery. Cells grew rapidly with a doubling time of 36-39 h and a plating efficiency of 26-28%. These cells exhibited an epithelial morphology and expressed cytokeratin. Tumor developed in severe combined immunodeficient (SCID) mice 4-6 wk after inoculated subcutaneously with the cultured cancer cells. Karyotypic analysis and comparative genomic hybridization (CGH) analysis in SHT-1 cells revealed a hypertriploid modal number of 76 with numerous numerical and structural abnormalities previously linked to colon cancer. In another cell line (SHH-1), CGH analysis revealed that -1p13 was the only cytogenetic anomaly.