Chromosome instability evaluated by fluorescence in situ hybridization in hereditary non-polyposis colorectal cancer.

Numerical aberrations of chromosome 17 and nuclear DNA content were compared in patients with hereditary non-polyposis colorectal cancer (HNPCC) and those with sporadic colorectal cancer (SCRC). During a period of 22 years, 30 cases (3.2%) from 28 families satisfied the Japanese clinical criteria of HNPCC. Using freshly frozen tissue samples, we investigated chromosomal aberration with fluorescence in situ hybridization with alpha satellite DNA probe for chromosome 17. Flow cytometric quantification of nuclear DNA content showed DNA aneuploidy in 9 of 15 patients (60.0%) with HNPCC and in 160 of 234 patients (68.4%) with SCRC, there was no significant difference between HNPCC and SCRC. The mean proportion of nuclei with aneusomy 17 (numerical chromosome aberration index: NCAI) in 14 patients with HNPCC was significantly higher than that in 42 patients with SCRC (46.8 +/- 5.0% vs 39.0 +/- 10.3%, P < 0.01). NCAI increased in proportion with the progression of the disease in SCRC (26.1% in stage I, 33.3% in stage II, 38.8% in stage IIIa, 42.7% in stage IIIb, and 46.2% in stage IV, P < 0.01), whereas NCAI in HNPCC was high in all stages (43.5%-49.2%). The proportion of patients with multiple numerical aberration of chromosome 17 was significantly higher in HNPCC (9/14) than among SCRC (11/42). Our data suggest that chromosome 17 is present in an unstable condition in HNPCC.

Aneusomy of chromosome 18 is associated with the development of colorectal carcinoma.

Specific loss of heterozygosity of chromosome 18 has been observed frequently in advanced colorectal carcinoma and is closely associated with its development. We investigated the prevalence of numerical aberrations of chromosome 18 in 44 specimens of colorectal carcinomas, using fluorescence in situ hybridization. We also examined the relationship between aneusomy of chromosome 18 and the clinicopathological features of these tumors. Aneusomy of the specimens (monosomy and polysomy) was determined when the same aneusomic population was detected in more than 15% of the nuclei. The frequency of monosomy and polysomy of chromosome 18 in colorectal carcinomas was 43% (19/44) and 29% (12/44), respectively. The prevalence of monosomy and polysomy 18 was significantly higher in cancers with invasion exceeding category T2 compared with T1 (P < 0.01), and with tumor size exceeding 20 mm in diameter compared with tumors less than 20 mm (P < 0.05). However, the prevalence of aneusomy 18 was not associated with other clinico-pathological features. The mean survival period and the 5-year survival rate after operation in patients with aneusomy 18 was not different from findings for those with disomy 18. Our results indicate that aneusomy of chromosome 18 is associated with the development of colorectal carcinoma; however, it is not a useful indicator of postoperative prognosis.

[Numerical aberration of chromosome 17 is correlated with multiple primary cancer in colorectal carcinoma].

Numerical aberration of chromosome 17 of 14 cases of colorectal carcinoma with multiple primary cancer (: multiple cancer) was compared with that of 35 cases of colorectal carcinoma without any other cancer (: single cancer). Fluorescence in situ hybridization with p17H8 was performed on touch smear from fresh materials. The proportion of aneusomy 17 (NCAI: numerical chromosome aberration index) in multiple cancers was significantly higher than that of single cancers (37.7 +/- 10.5% VS 46.1 +/- 8.0%; p < 0.01). Although NCAI of single cancers conformed to cancer progression (26.1 +/- 4.7% in Dukes A, 33.1 +/- 7.1% in Dukes B, 39.9 +/- 6.9% in Dukes C, and 45.7 +/- 12.0% in Dukes D), that of multiple cancers was high in all stages (44.7 +/- 7.3%, 44.4 +/- 6.8%, 50.4 +/- 11.2%, and 49.6 +/- 5.6%, respectively). Furthermore, the multiple numerical aberration of chromosome 17 in multiple cancers was more often than that of single cancers (64.3% VS 22.9%; p < 0.01).

[Flow cytometric quantification of numerical chromosome aberrations in non-small cell lung carcinomas using formalin-fixed paraffin-embedded tissue].

Fluorescence in situ hybridization with biotinylated repetitive DNA probe specific for the centromeric region of chromosome 17 (p17H8: Oncor) was applied to suspended nuclei which were isolated by Shutte's method from formalin-fixed paraffin-embedded tissue. The tissues were obtained from surgically resected specimens from nine patients with non-small cell lung carcinoma. The isolated nuclei were prepared with 0.05% pepsin/0.1NHCl for 15 minutes at 37 degrees C. Subsequently, these were immersed in 70% acetic acid for 10 seconds at room temperature. After heat denature with hybridization mixture which contained 3 mu 1 DNA probe for 10 minutesat 70 degrees C, 1 x 10(6) nuclei were incubated overnight at 37 degrees C. After washing with 60% formamide/2 x SSC, the hybridized probes were labeled by FITC conjugated avidin. A number of centromeric signals of chromosome 17 wasevaluated by fluorescence microscopy (BH-2, Olympus). Furthermore, a probe-related FITC intensity was quantified using flow cytometry (FACScan, Becton Dickinson). As the results, there was good correlation between a relative fluorescence intensity determined by flow cytometry and a relative fluorescence signal by fluorescence microscopy (p < 0.05).

[A case of solitary splenic metastasis from colon cancer].

A 58-year-old male who had a left hemicolectomy for descending colon cancer on July 1, 1993 was admitted to our hospital. A CT scan revealed a homogeneous low-density mass in the inferior portion of the spleen. Under the diagnosis of solitary splenic metastasis, a splenectomy was performed on August 10, 1995. Histologically, splenic tumor revealed moderately differentiated adenocarcinoma consistent with the primary tumor. Flow cytometric analysis revealed DNA diploidy in the primary tumor, and DNA aneuploidy (DNA index = 1.76) in the metastatic tumor. Using fluorescence in situ hybridization with p17 H8, numerical aerrations of chromosome 17 were observed in the primary tumor.