Near diploid large bowel carcinomas have better five-year survival than aneuploid ones

Prognostic Significance of DNA Aneuploidy and p21ras Oncoprotein Expression in Colorectal Cancer and Their Role in the Determination of Treatment Modalities

The purpose of the present study was to investigate the prognostic significance of DNA ploidy, S-phase fraction and p21ras oncoprotein expression in patients with colorectal cancer and to correlate these factors with the clinical behavior of the tumors and their response to therapy. Of 79 patients with colorectal cancer 57% (45/79) had early stage disease. Forty-one percent (32/79) had aneuploid tumors while 30% (24/79) of the tumors had a high (>10%) S-phase fraction. p21ras oncoprotein expression was detected in 38% (30/79) of tumors. Patients with aneuploid tumors had a worse prognosis than patients with diploid tumors (p=0.0002). Similarly, patients with high S-phase fraction tumors had a shorter survival than those with low S-phase fraction tumors (p=0.005). No such difference was found between p21ras-positive and p21ras-negative tumor subgroups. In early stage colorectal cancer, aneuploidy was closely correlated with disease outcome (p=0.029). Early stage patients with diploid tumors who received radiotherapy and chemotherapy had a better prognosis than patients with aneuploid tumors. In conclusion, DNA ploidy is a significant and independent prognostic factor in colorectal cancer. Aneuploidy and genetic alteration of the p21ras oncoprotein are important in determining the biological aggressiveness of colorectal cancer. Furthermore, DNA ploidy may identify those subgroups of patients with early stage disease who may benefit from more aggressive treatment.

Stage-specific frequency and prognostic significance of aneuploidy in patients with sporadic colorectal cancer--a meta-analysis and current overview

PURPOSE

Aneuploidy has long been suggested as an independent prognostic marker for colorectal cancer (CRC) patients and could thus aid for individualized medicine. However, due to a large spectrum of deviating studies, expert panels do not recommend ploidy assessment. In order to clarify a potential bias of stage-specific frequency of aneuploidy, we now conducted a meta-analysis combined with a systematic review regarding aneuploidy and prognosis.

METHODS

A systematic, web-based search process retrieved 1935 studies published in English between 1990 and 2011. The defined endpoint for the meta-analysis was an increase in aneuploidy frequency between early- (Dukes A, B and UICC I, II; n = 3632 samples) and late-stage (Dukes C, D and UICC III, IV; n = 3440 samples) colorectal carcinomas.

RESULTS

Of 1935 studies initially identified, 17 image (2130 patients) and 20 (7023 patients) flow cytometric studies were analyzed in detail. The meta-analysis (7072 patients) revealed late-stage CRC to be more frequently aneuploid than early-stage CRC (odds ratio 1.51, 95 % CI 1.37-1.67; p = 0.0007). Independent of tumor stage, the overall range of aneuploidy was 39 to 81 % (median 58 %), and altogether, 21 (54.1 %) studies described a significant prognostic impact of aneuploidy for overall, disease-specific, and recurrence-free survival, respectively.

CONCLUSIONS

A substantial number of studies showed a prognostic importance of aneuploidy in CRC. Furthermore, the higher frequency of aneuploidy in late-stage CRC implies an increase in genomic instability with CRC progression, indicating aneuploidy to be also a stage-specific prognostic marker.

DNA ploidy status and prognosis in colorectal cancer: a meta-analysis of published data

PURPOSE

In colorectal cancer, the negative effect of aneuploidy has been a controversy for more than 20 years. Studies to determine a survival-deoxyribonucleic acid content relationship have conflicting results. A systematic literature search followed by a meta-analysis of published studies addressing prognostic effect of aneuploidy for patients who underwent surgical treatment of colon and rectal cancer was conducted.

METHODS

The main outcome measure was the five-year overall mortality rate after surgical resection. For the selected studies, we estimated this outcome for three subsets of patients through separate meta-analyses: 1) for all patients with colorectal cancer; 2) only between patients with Stage II colon cancer; and 3) only for studies in which follow-up losses were declared. The presence of publication bias was assessed with a funnel plot for asymmetry.

RESULTS

A total of 5,478 patients with colorectal cancer were represented in 32 studies (Group 1), we estimated a reduction in the five-year overall mortality from 43.2 percent for aneuploid tumors to 29.2 percent for diploid tumors (combined relative risk = 1.44; 95 percent confidence interval = 1.34-1.55; P < 0.001). In addition, 357 patients with Stage II colon cancer (Group 2) extracted from three studies had an absolute reduction of 14.3 percent in five-year overall mortality favoring diploid tumors (combined relative risk = 1.93; 95 percent confidence interval = 1.29-2.89; P = 0.001). Lastly, of 14 studies in which follow-up losses were declared (Group 3), 2,221 patients were represented and a 15.7 percent mortality reduction was measured favoring patients with diploid tumors (combined relative risk = 1.44; 95 percent confidence interval = 1.3-1.61; P < 0.001).

CONCLUSIONS

Patients who undergo an aneuploid colorectal cancer surgical resection have a higher risk of death after five years. This finding may ultimately impact survival of patients with node-negative colon cancer through adjuvant therapy.

Strong HLA-DR expression in microsatellite stable carcinomas of the large bowel is associated with good prognosis

Progression of colorectal cancer may follow either of two main genetic routes: the chromosome- or microsatellite-instability pathways. Association between the patients' prognosis and microsatellite instability has been questioned. Improved survival has previously been found in patients with expression of HLA-DR antigens on their tumour cells. In this study, the expression of HLA-DR antigen was investigated by immunohistochemistry in 357 large bowel carcinomas stratified by microsatellite instability status. Sixteen per cent of the tumours showed strong HLA-DR expression and 35% had weak DR expression. We confirmed that patients with strong positive HLA-DR staining had improved survival (P<0.001) compared to patients with no HLA-DR expression. Strong epithelial HLA-DR staining was significantly associated with high level of microsatellite instability (P<0.001). In the subgroup of tumours with characteristics typical of the chromosomal instability phenotype, i.e. in microsatellite-stable tumours, the patients positive for the HLA-DR determinants showed better survival than those without HLA-DR expression. The protective effect of HLA-DR expression on survival was confirmed by multivariate analysis, both in the whole patient group and in the microsatellite-stable/microsatellite instability-low group. This might be explained by enhanced T-cell mediated anti-tumour immune responses against tumour cells in the HLA-DR positive tumours. The finding of better patient survival in the subgroup of strong HLA-DR positive microsatellite-stable tumours may have clinical implications for these patients.

DNA index and S-phase fraction in curative resection of colorectal adenocarcinoma: analysis of prognosis and current trends

The DNA index (DI) and S-phase fraction (SPF) have been said to be independent factors in colorectal adenocarcinoma and have a different distribution from the clinicohistologic parameters. This study assesses the real efficacy of DI and SPF for curative resection of colorectal adenocarcinomas with respect to the prognosis and the clinicohistologic parameters. From July 1991 to October 1994 a total of 666 patients underwent curative resection of colorectal adenocarcinoma and DNA flow cytometry in Kaohsiung Chang Gung Memorial Medical Center Hospital, Taiwan. We defined diploid tumors as having a DI of ? 0.9 but <1.1 and a nondiploid tumor as having a DI of <0.9 OR > 1.1. A high SPF was defined as being more than the median value for the total SPF. Altogether, 495 cases (74.32%) had a 5-year cancer-free survival. Tumor stage, DI, tumor location, and tumor morphology were associated with significant cancer-free survival in the univariate analysis (p = 0.0295, <0.001, 0.0357, and <0.001, respectively). After all factors were entered into the multivariate analysis, the independent factors for cancer-free survival were found to be stage, tumor location, and morphology (p < 0.001, 0.012, and 0.044, respectively). In cases distinguished by the DI, diploid tumors had significantly more frequent right colon locations (p <0.001). After cases were separated by the SPF (median value 18.4%), better histology (well differentiated adenocarcinoma) was noted with a low SPF (p = 0.017). No other clinicohistologic parameters had significant differences shown by the DI or SPF. Thus DI and SPF failed to appear as independent factors for 5-year cancer-free survival. The independent factors for curative colorectal adenocarcinoma were tumor stage, location, and morphology. Diploid tumors were located at the right colon more often, and low SPF indicated better histology in the univariate analysis.

p53 nuclear accumulation and multiploidy are adverse prognostic factors in surgically resected stage II colorectal cancers independent of fluorouracil-based adjuvant therapy

To identify the prognostically highest risk patients, DNA content and p53 nuclear or cytoplasmic accumulation, evaluated by monoclonal antibody DO7 and polyclonal antibody CM1, were determined in 94 surgically resected stage II (Dukes B2) colorectal cancers, treated or not with adjuvant 5-fluorouracil-based chemotherapy. Sixty-one (65%) of the tumors were aneuploid, 16 (17%) of which had a multiploid DNA content; 50 (53%) displayed DO7 nuclear p53 accumulation, and 44 (47%) showed cytoplasmic CM1 positivity. In multivariate analysis, only multiploidy and p53 nuclear positivity emerged as independent prognostic indicators of a poorer outcome. Positivity for p53 was associated with shorter survival in 5-fluorouracil-treated and untreated patients. Therefore, in patients with Dukes B2 colorectal cancer, a biologic profile based on the combined evaluation of DNA multiploidy and p53 status can provide valuable prognostic information, identifying patients to be enrolled in alternative, more aggressive therapeutic trials.

DNA amplification and chromosomal translocations are accompanied by chromosomal instability: analysis of seven human colon cancer cell lines by comparative genomic hybridization and spectral karyotyping

Genetic instability in human cancers is classified as chromosomal instability (CIN) or microsatellite instability (MIN). DNA amplification and translocations are observed frequently in various cancers. We used comparative genomic hybridization (CGH) and spectral karyotyping (SKY) to study seven human colon cancer cell lines and investigate the relations among genetic instability, DNA amplification, and chromosomal translocations. DNA amplification was found in five cell lines (COLO320DM, COLO201, WiDr, CoCM-1, and CACO-2), and all were aneuploid. In these five cell lines, segments of chromosomes were translocated to other chromosomes. In contrast, cell lines with MIN, DLD-1, and LoVo did not show DNA amplification. The LoVo cells with MIN were considered near diploid and contained translocations. These findings suggest that DNA amplification and chromosomal translocations are accompanied by CIN.

Microsatellite instability: application in hereditary non-polyposis colorectal cancer

Colorectal cancer (CRC) is a significant cause of mortality in Western populations. About 15% of CRC patients report a family history of the disease. Studies on individuals with a genetic predisposition to CRC have been responsible for significant advances in the understanding of this disease. Thus, although developments in molecular biology have been mainly restricted to a minority of individuals with a hereditary background, information obtained from this group may affect the diagnosis and therapy of sporadic CRCs as well. Deficiency in the DNA mismatch repair (MMR) system results in microsatellite instability (MSI). Individuals from hereditary non-polyposis colorectal cancer (HNPCC) kindreds with germline mutations in genes involved in MMR may benefit from clinical screening programs. The higher frequency of MSI in HNPCC than in sporadic tumours suggests that involvement of MMR genes in sporadic adenomas may be uncommon. Consequently

A strategy combining flow sorting and comparative genomic hybridization for studying genetic aberrations at different stages of colorectal tumorigenesis in ulcerative colitis

BACKGROUND

DNA aneuploidy has been shown to increase the risk of developing dysplasia in ulcerative colitis (UC) and is related to tumorigenesis in the colorectum. Therefore, it is of particular interest to study genetic aberrations behind DNA aneuploidization during colorectal carcinogenesis. We wanted to elucidate further the relationship between mucosal morphology and DNA aberrations in UC.

METHODS

DNA flow cytometry was applied to multiple lesions including regenerative, dysplastic, and carcinomatous mucosa from the colectomy specimen of a male patient with long-standing UC. The lesions harbored multiple DNA aneuploid stemlines that were subjected to flow sorting. We analyzed gene alterations by degenerate oligonucleotide primer (DOP; universal primers) polymerase chain reaction (PCR)-based comparative genomic hybridization (CGH) and fluorescent in situ hybridization (FISH) in diploid and aneuploid sorted cells.

RESULTS

DOP-PCR-based CGH shows gains and losses that can be verified by FISH. We show that with this approach one can study genetic evolution of distinct DNA diploid and aberrant subpopulations through defined stages of colorectal tumorigenesis. This includes getting information related to tumor heterogeneity that cannot be obtained by CGH with DNA extracted from nonsorted cell populations. Genetic imbalance was also detected in diploid nondysplastic flow-sorted mucosal cells from the same bowel.

CONCLUSIONS

Similar gains and losses were found in aneuploid dysplasias and carcinomas at widely separated locations in the same bowel, indicating a common selection pressure in different areas of the same bowel. The common aberrations may be of importance for progression from dysplasia to carcinoma.

DNA ploidy in colorectal cancer, heterogeneity within and between tumors and relation to survival

Flow cytometry was used to study the incidence of aneuploidy and to determine the significance of multiple sampling from colorectal tumors. DNA ploidy pattern has been proposed as a supplementary prognostic marker, but discrepancies in findings are major. DNA clonal heterogeneity, defined as two or more DNA aneuploid stemlines in the same tumor, is well established. However, most studies have been based on only one biopsy from each tumor. In our study multiple biopsies were taken from 163 patients (88 males and 75 females) electively operated for colorectal cancer. Tumor cells were harvested by fine needle aspiration from fresh frozen biopsies sampled at different sites of each tumor. DNA aneuploidy was detected in tumors from 145 patients (89%), and 18 patients (11%) had a solitary DNA diploid cell population. In a 79 month follow-up period 105 patients had died. Statistical analysis showed that distinction between diploidy and aneuploidy did not predict survival. However, grouping subpopulations into DNA diploid plus near diploid (DNA index (DI) 0. 97-1.15), DNA aneuploid with all aneuploid subpopulations in the interval 1.15-2.06, and DNA aneuploid with subpopulations with DI < 0.97 and/or DI > 2.06, showed a significant difference in survival in a Cox multivariate analysis including Dukes' stage P = 0.049 comparing the second group to the first and P = 0.01 comparing the third group to the first. In 21 (13%) patients only one subpopulation was found, 57 (35%) had two, 44 (27%) had three, and 41 (25%) had four or more different subpopulations. The association of DNA ploidy to survival is shown to be dependent on the number of biopsies analysed.

Prognostic significance of DNA ploidy, S-phase fraction, and P-glycoprotein expression in colorectal cancer

BACKGROUND AND OBJECTIVES

Parameters that allow prediction of the disease course in colorectal cancer would aid the development of improved treatment strategies. For this reason, we evaluated the prognostic value of flow cytometric DNA ploidy and S-phase fraction (SPF) and P-glycoprotein (Pgp) expression in this type of tumor.

METHODS

The prognostic significance of DNA ploidy, SPF, and Pgp expression on paraffin-embedded sections from 107 patients with colorectal carcinoma was determined. The mean follow-up was 36.6 months (range = 3-72 months). DNA ploidy and SPF were evaluated by flow cytometry and Pgp by immunohistochemistry using monoclonal antibody C219. The Cox regression model was used to adjust for several clinical and pathologic covariates.

RESULTS

Of the 107 carcinomas examined, 44 (41.1%) were classified as DNA diploid and 63 (58.9%) as DNA aneuploid. DNA ploidy pattern was significantly related to tumor site (P = 0.010), tumor stage (P = 0.016), and vascular invasion (P = 0.015) but not to other clinicopathologic variables. Patients with DNA diploid tumors showed a better survival rate than did those with aneuploid tumors. After stage IV disease was excluded, patients with diploid tumors also presented a better disease-free and overall survival than did patients with aneuploid tumors. Mean SPF of the whole series was 13.5% (median = 11.3%, range = 1.4%-29.9%). Aneuploid tumors had a higher median SPF than did diploid tumors (17 vs. 6.2; P = 0.0001). SPF was only related significantly with tumor location (P = 0.026). In the multivariate analysis, SPF was a significant independent prognostic factor for overall survival (P = 0.01). When stage IV was excluded, SPF was also an independent prognostic variable for both disease-free (P = 0. 02) and overall (P = 0.01) survival. Of 107 tumors, 61 (57%) were positive for Pgp expression, but no relation was found between this and other clinicopathologic parameters. Pgp expression had no influence on survival.

CONCLUSIONS

Our results suggest that flow cytometric DNA ploidy and SPF are significant and independent prognostic factors in patients with colorectal carcinoma, whereas Pgp expression is not.

Chromosomal gains and losses in primary colorectal carcinomas detected by CGH and their associations with tumour DNA ploidy, genotypes and phenotypes

Comparative genomic hybridization (CGH) is used to detect amplified and/or deleted chromosomal regions in tumours by mapping their locations on normal metaphase chromosomes. Forty-five sporadic colorectal carcinomas were screened for chromosomal aberrations using direct CGH. The median number of chromosomal aberrations per tumour was 7.0 (range 0-19). Gains of 20q (67%) and losses of 18q (49%) were the most frequent aberrations. Other recurrent gains of 5p, 6p, 7, 8q, 13q, 17q, 19, X and losses of 1p, 3p, 4, 5q. 6q, 8p, 9p, 10, 15q, 17p were found in > 10% of colorectal tumours. High-level gains (ratio > 1.5) were seen only on 8q, 13q, 20 and X, and only in DNA aneuploid tumours. DNA aneuploid tumours had significantly more chromosomal aberrations (median number per tumour of 9.0) compared to diploid tumours (median of 1.0) (P < 0.0001). The median numbers of aberrations seen in DNA hyperdiploid and highly aneuploid tumours were not significantly different (8.5 and 11.0 respectively; P = 0.58). Four tumours had no detectable chromosomal aberrations and these were DNA diploid. A higher percentage of tumours from male patients showed Xq gain and 18q loss compared to tumours from female patients (P = 0.05 and 0.01 respectively). High tumour S phase fractions were associated with gain of 20q13 (P = 0.03), and low tumour apoptotic indices were associated with loss of 4q (P = 0.05). Tumours with TP53 mutations had more aberrations (median of 9.0 per tumour) compared to those without (median of 2.0) (P = 0.002), and gain of 8q23-24 and loss of 18qcen-21 were significantly associated with TP53 mutations (P = 0.04 and 0.02 respectively). Dukes' C/D stage tumours tended to have a higher number of aberrations per tumour (median of 10.0) compared to Dukes' B tumours (median of 3.0) (P = 0.06). The low number of aberrations observed in DNA diploid tumours compared to aneuploid tumours suggests that genomic instability and possible growth advantages in diploid tumours do not result from acquisition of gross chromosomal aberrations but rather from selection for other types of mutations. Our study is consistent with the idea that these two groups of tumours evolve along separate genetic pathways and that gross genomic instability is associated with TP53 gene aberrations.

DNA index shift with disease progression in colorectal adenocarcinoma: a morphological and flow cytometric study

DNA index (DI) values seen in 86 sporadic colorectal adenocarcinomas were related to clinical, morphological, and disease progression features. DI, whose overall distribution was bimodal with peaks in the diploid and from hypotriploid to tetraploid ranges, was related to pathological lymph node staging (pN), staging, lymphoid reaction, and tubular configuration. With increasing severity in pathological features, an irregular shift in DI class prevalence was seen, with no steady increase from diploidy to higher degrees of aneuploidy. All UICC stage I tumors (13% of total) were aneuploid, 50% being hypertriploid; diploidy (35%) and hypertriploidy (22%) prevailed in stage II carcinomas (41% of total), diploidy (35%) and hypotriploidy (30%) in stage III (30% of total), and triploidy (33%) in stage IV (15% of total). Amongst features related to stage (lymphoid reaction, depth of neoplastic embolization, grading, tubular configuration, and polymorphism), few were associated with DI, and none influenced DI shift and class prevalence through the stages. The biological capabilities of colorectal adenocarcinoma in relation to stage are expressed by certain aneuploid DI classes (hypertriploidy: absence of extracolonic spread; hypotriploidy: lymph node metastases; triploidy: distant metastases). Diploidy is unrelated to criteria defining stage above I and predicts 50% of cases with development of metachronous metastases. Irregular DI class shift through the stages may be attributable to different pathways of cancerogenesis and disease progression in diploid versus aneuploid carcinomas. Alternatively, assuming that the diploid fraction in aneuploid tumors contains neoplastic cells, pure diploid carcinomas represent the selection of a vital clone that may give rise to a further mixed population whose aneuploid DI is different and best fitted to express the biological capabilities of that given stage.

Prognostic significance of DNA ploidy in patients with stage II and stage III colon carcinoma: a prospective flow cytometric study

BACKGROUND

The prognostic value of flow cytometric DNA ploidy in colorectal carcinoma has not been defined clearly. Most previous studies were conducted retrospectively using archival formalin fixed, paraffin embedded tumor samples. Conversely, few data on prospective studies employing fresh or frozen tissue specimens are available. There is general agreement that fresh/frozen material is more reliable than paraffin embedded tissue for DNA ploidy analysis by flow cytometry.

METHODS

In the current investigation we evaluated the prognostic significance of nuclear DNA content in a prospective series of 191 patients with curatively resected TNM Stage II (n = 107) or Stage III (n = 84) sporadic colon carcinomas. DNA ploidy status was assessed by flow cytometry utilizing multiple frozen tumor samples. Mean follow-up in surviving patients was 48.5 months (median, 46.9 months; range, 29-77 months). The Cox proportional hazards model was used to adjust for several clinical and pathologic covariates.

RESULTS

Of the 191 carcinomas examined, 47 (24.6%) were classified as DNA diploid and 144 (75.4%) as DNA aneuploid. DNA ploidy pattern was significantly related to tumor site (P < 0.0001), histologic type (P = 0.0002), and grade of differentiation (P = 0.009), but not to other clinical and pathologic variables. Patients with DNA diploid tumors showed a better disease free (P = 0.013) and overall survival (P = 0.021) than patients with DNA aneuploid adenocarcinomas. In particular, patients with Stage II DNA diploid tumors (n = 30) had an excellent clinical outcome, with an overall 5-year survival rate of 97%. When patients were analyzed according to the anatomic site of the tumor, a significant relationship between DNA ploidy status and disease free and overall survival was observed in the group of patients with carcinomas of the proximal colon (n = 84) (P = 0.004 and P = 0.002, respectively), but not among patients whose tumors were sited distally to the splenic flexure (n = 107). In multivariate analysis, nuclear DNA content was demonstrated to be an independent prognostic variable for both disease free and overall survival. Furthermore, in the group of patients with tumors of the proximal colon, DNA ploidy pattern was the single most important prognostic factor.

CONCLUSIONS

Our results confirm that flow cytometric DNA ploidy status is a significant and independent prognostic factor in patients with colon carcinoma. These findings may have clinical implications for the management of affected patients, especially those with Stage II disease.

K-ras mutations and prognosis in large-bowel carcinomas

BACKGROUND

Colorectal carcinogenesis is regarded as a multistep process involving several genetic alterations, with mutation in the K-ras gene in about half of the tumours. We aimed at clarifying the role of this genetic alteration related to survival and clinicopathologic variables.

METHODS

One hundred large-bowel carcinomas operated on between 1978 and 1982 were studied for the presence of point mutations in codons 12 and 13 of the K-ras gene, using enriched polymerase chain reaction amplification, restriction fragment length polymorphism analysis, and direct sequencing.

RESULTS

Forty mutations were found (40%): 31 in codon 12 and 9 in codon 13, 7 different types. There was no relationship between tumours with and without K-ras mutations with regard to Dukes' stages, age or sex of the patient, tumour localization, histologic grade, DNA ploidy pattern, HLA-DR staining pattern, or survival. Samples from 5 different localizations in 7 carcinomas showed identical K-ras mutation pattern, as did 19 recurrences/ metastases originating from 11 carcinomas.

CONCLUSIONS

When present, the primary tumour shows homogeneous distribution of K-ras mutation, and the mutation follows the carcinoma in the secondary deposit, regardless of lymphogenous or hematogenous spread. The presence of K-ras mutation does not seem to have prognostic significance for the patient, and the precise nucleotide change is furthermore not predictive of tumour behaviour.

Prognostic evaluation of DNA flow cytometric and histopathologic parameters of colorectal cancer

BACKGROUND

The clinical value of DNA flow cytometry of colorectal cancer is unclear. The purpose of this retrospective study was to evaluate the relationship between tumor flow cytometry, histopathologic parameters, and survival.

METHODS

Flow cytometry was performed on paraffin embedded specimens from 653 patients who had surgery from 1980 to 1983.

RESULTS

Aneuploidy was associated with distal tumor, perineural invasion, desmoplastic reaction, and failure to secrete mucin. TNM Stage I tumors were more frequently diploid than were more advanced tumors (71% vs. 41%). An abnormal DNA content had a marginal impact on survival as evaluated by univariate analysis (69% vs. 61% 10-year survival rate, P = 0.06). Multivariate analysis revealed that significant predictors of outcome were lymph node metastasis (95% confidence interval of relative risks of death from recurrent disease, 1.50-2.92), rectal cancer (1.22-2.19), absence of lymphocytic infiltration (1.20-2.17), invasion through bowel wall (1.17-3.13), lymphatic vessel invasion outside bowel wall (1.05-2.69), perineural invasion (1.15-3.19), and male gender (1.00-1.79).

CONCLUSIONS

These findings suggest that ploidy is associated with some histopathologic parameters, but flow cytometry does not correlate with long term survival of patients with colorectal carcinoma.

Biologic and clinical correlations among ploidy, cell kinetics, and the tumor-associated glycoprotein-72 tissue expression in colorectal cancer. Preliminary findings

PURPOSE

The aim of this study was to evaluate the possibility of identifying biologically aggressive subgroups of patients, combining several biologic parameters such as the tumor and normal mucosa values from the ploidy, the S-phase cell percentage, and tumor-associated glycoprotein-72 (TAG-72) expression.

METHODS

One hundred five colorectal cancer patients were studied to analyze the possible prognostic role of ploidy and cell kinetics in multiple fresh specimens from the tumor and normal mucosa. Since the presence of TAG-72 in the colonic mucosa has been correlated to neoplastic transformation, the correlations between these parameters and the quantitative tissue expression of the TAG-72 were analyzed in a subgroup of 53 cases.

RESULTS

A significantly lower five-year disease-free survival rate (21.4 percent) was observed in patients with multiploid tumors, when compared with that observed in patients with diploid or single aneuploid tumors (67.5 percent) (P = 0.03). The quantitative tissue TAG-72 expression contributed in identifying a particular patient subgroup (20 percent), characterized by S-phase percentage and TAG-72 values from the normal mucosa that were unexpectedly higher than 12.1 percent and 7.5 U/mg of proteins, respectively. In particular, when the 25 Dukes B patients were analyzed, similar results were observed. In fact, 14 (56 percent) cases showed high tumor cell proliferation and, surprisingly, a high tissue TAG-72 content in the normal mucosa was found in 4 (28.6 percent) of these patients.

CONCLUSIONS

Other than multiploidy, the biologic aggressiveness of colorectal cancer might be successfully assessed introducing the evaluation of new biologic parameters, such as the TAG-72 content and S-phase percentage values of the normal mucosa, suggesting the possibility of further stratifying this patient population.

Application of the crypt-isolation technique to flow-cytometric analysis of DNA content in colorectal neoplasms

BACKGROUND/AIMS

Conventional flow-cytometric analysis of colorectal tumor DNA content includes both tumor and stromal cell DNA. To improve the method, we evaluated the DNA content of purified epithelial cells using the crypt-isolation technique.

METHODS

Normal and neoplastic crypts were isolated from fresh resected colorectum nonenzymatically. Isolated crypts were digested into single nuclei suspensions and examined by flow cytometry (FCM). Internal controls from normal crypts were used to define diploidy. The neoplastic nuclei in the same individual and mixtures of both normal and neoplastic nuclei in various ratios were analyzed.

RESULTS

Tumors having both diploid and aneuploid stemlines were found more frequently than that reported using conventional FCM. Near-diploid DNA stemlines with DNA indices ranging between 0.90 and 1.10 were detectable. The cases of advanced cancer in which the DNA index was between 0.90 and 0.95 were associated significantly with Dukes' stage C.

CONCLUSIONS

This is the first reported analysis of the DNA content of "pure" neoplastic colorectal epithelia using FCM. Multiploid and near-diploid stemlines were more accurately analyzed than that using conventional FCM.

Relationships among tenascin expression, DNA ploidy patterns, and multidrug resistance gene product (P-glycoprotein) in human colon carcinoma

Relationships among tenascin expression, DNA ploidy, and P-glycoprotein were examined in 81 primary human colon cancers and 61 metastatic lymph nodes. First, the DNA ploidy patterns of colon cancerous tissue surrounded (TN+) and not surrounded (TN-) by tenascin immunoreactivity were investigated. Then the expression of P-glycoprotein, one of two multidrug resistance gene products, was examined in TN+ and TN- colon cancer tissues by immunohistochemistry. Aneuploid DNA patterns were observed at high frequency in TN- colon cancer tissues (37/61) and metastatic lymph nodes (44/52). In contrast, diploid DNA patterns were observed predominantly in TN+ colon cancer tissues (50/56). Although P-glycoprotein expression was observed in primary TN+ and TN- colon cancer (9/81), the level of P-glycoprotein expression was not correlated with DNA aneuploidy in TN- colon cancer tissues. Overall, reduced tenascin expression was correlated well with DNA aneuploidy, but no significant correlation was found between DNA aneuploidy and P-glycoprotein appearing when cancer cells become resistant to several anti-cancer drugs. Thus, tenascin may play an important role in preventing colon cancer cells from invading surrounding tissues.

Tumor aneuploidy in young patients with colorectal cancer

BACKGROUND

Colorectal cancer in young patients (40 years of age or younger) often is considered to have a worse prognosis than in older patients. The authors studied tumor DNA status and stage of disease to determine whether tumors in younger patients behaved differently from tumors in older patients.

METHODS

This retrospective study identified 33 young patients with colorectal cancer treated surgically between 1979 and 1989. The DNA content of the tumors was analyzed by DNA flow cytometry. Results were compared with 75 cases of colon cancer in patients older than 40 years of age.

RESULTS

Six of the 33 young patients had inadequate tissue for study. Four patients with ulcerative colitis were excluded. Tumor aneuploidy was present in 14 of 23 young patients (61%; mean age, 35 years) and 46 of 75 older patients (61%; mean age, 71 years). When Dukes staging was performed for the young patients, one had Stage A (4%), nine had Stage B (39%), eight had Stage C (35%), and five had Stage D (22%) disease. The control group had similar staging. The distribution of aneuploid tumors within each Dukes stage was also similar. Twenty-one young patients were available for follow-up. Four (31%) of 13 patients with aneuploid tumors died, whereas none of 8 patients with diploid tumors died. This trend was not statistically significant (P < 0.10).

CONCLUSIONS

The frequency of tumor aneuploidy, stage of disease at presentation, and distribution of tumor aneuploidy within each stage was similar when young and old patients with colorectal cancer were compared. There is a trend toward tumor aneuploidy being associated with a poorer prognosis in young patients.

Strong HLA-DR expression in large bowel carcinomas is associated with good prognosis

One hundred large bowel carcinomas operated on between 1978 and 1982 were studied immunohistochemically with regard to expression of HLA-DR antigens. Three sections from each tumour were investigated by a semiquantitative scoring system, and a mean score for each patient established. Based on this scoring system, the tumours were divided into three groups: 0; 0.1-1.0; and > 1.0. All patients were followed until death (n = 68) or until June 1, 1992, and all cancer-specific deaths (n = 56) have been recorded. Analysis of survival in the whole patient group showed significant difference between the three levels of tumour HLA-DR expression (P = 0.006); patients who had tumours with strong HLA-DR expression showing the best survival. In a stratified analysis after Dukes' stages there was still a significant difference (P > 0.001) between the three levels of HLA-DR staining intensity. After a multiple regression analysis (Cox) with correction for different variables, the HLA-DR expression maintained its significance as a risk factor. To our knowledge this is the first time a relationship between intensity of tumour DR expression and survival has been shown in large bowel carcinoma.

Flow cytometric analysis of ploidy in colorectal cancer: a multicentric experience

Ploidy and cell proliferation determined by flow cytometry were assessed on colorectal cancers from patients admitted to two Italian cancer research centres. A total of 181 patients were followed prospectively for 4 years at the Istituto Regina Elena (IRE) of Rome and at the Istituto Nazionale Tumori (INT) of Milan. Fresh (at the IRE) or frozen (at the INT) tumour material and similar procedures were used for subsequent sample preparation. Similar frequencies of aneuploid tumours (63% vs 66%) and superimposable median DNA indices (1.6) were observed for the two case series. In both series, DNA ploidy was generally unrelated to clinico-pathological factors, except for a higher frequency of aneuploid tumours in Dukes' D (88%) than in Dukes' A stage (33%) in the IRE experience. DNA ploidy was a weak prognostic indicator at 3 years but not at 4 years in the IRE case series, and it never exhibited a clinical relevance in the INT experience. Conversely, multiploidy was an indicator of worse relapse-free and overall survival at 4 years in the IRE and INT case series.

The TP53 tumour suppressor gene in colorectal carcinomas. II. Relation to DNA ploidy pattern and clinicopathological variables

Heterozygous loss of the TP53 gene on chromosome arm 17p in colorectal carcinomas was strongly associated with DNA aneuploidy (P < 0.0001). This association was seen only in tumours with loss on both 17p and 17q (P < 0.001), but not for loss on 17p only. DNA near diploid (ND) carcinomas and DNA aneuploid (AN) tumours with DNA index > or = 1.1 and < 1.3 had similar frequencies of TP53 gene loss (49% and 42%, respectively), whereas AN tumours with DNA index > or = 1.3 had a significantly higher frequency of TP53 gene loss (85%) (P < 0.0001 and P < 0.0001, respectively). There was a significant association between loss of the TP53 gene and histological grade (P < 0.01), and there tended to be an association between loss of the TP53 gene and degree of cellular atypia (P < 0.05), with TP53 gene loss being most frequent in moderately differentiated carcinomas, and in carcinomas with severe cellular atypia, respectively. The proportion of tumours with loss of the TP53 gene increased significantly towards the distal part of the large bowel (P < 0.0001). These results indicate that different genetic mechanisms may be involved in the carcinogenesis in colon and rectum carcinomas, and in the two subsets of DNA aneuploid carcinomas. Furthermore, the data may suggest a role for the TP53 gene in the aneuploidisation process, possibly as a 'target' for a whole chromosome loss.

Serum carcinoembryonic antigen in relation to survival, DNA ploidy pattern, and recurrent disease in 406 colorectal carcinoma patients

Serum carcinoembryonic antigen (CEA) levels in relation to survival, flow cytometric DNA ploidy pattern, Dukes stage, and recurrent disease was prospectively evaluated in 406 patients with colorectal carcinoma. In 246 patients (61%) the carcinomas were DNA aneuploid. Increased preoperative CEA levels (> 5 micrograms/l) were found in 151 of 363 evaluable patients (42%). Dukes stage-B patients with preoperative CEA elevation showed significantly poorer prognosis than those with normal CEA values (p = 0.001). A weak but significant correlation was found between preoperative CEA level and Dukes stage (Kendall's tau = 0.25, p < 0.01). Of 50 evaluable patients with clinical recurrence and postoperative normal or normalized CEA levels, 28 (56%) had a rise in CEA before or at the time of clinical recurrence. The sensitivity of the CEA test for primary and for recurrent disease was not significantly different in the DNA aneuploid and the DNA near-diploid groups.