Clinical importance of DNA content in rectal cancer measured by flow cytometry

Radioprotective effect of nanoniosome loaded by Mentha Pulegium essential oil on human peripheral blood mononuclear cells exposed to ionizing radiation

OBJECTIVE

The present study aimed to assess the radioprotective effect of nanoniosomes loaded by Mentha Pulegium essential oil (MPEO-N nanoparticles) as a natural antioxidant on human peripheral blood mononuclear cells (PBMCs).

SIGNIFICANCE

Despite the applications and advantages of ionizing radiation, there are many radiation risks to biological systems that are necessary to be reduced as much as possible.

METHODS

MPEO-N nanoparticles were prepared by the lipid thin film hydration method, and its physicochemical characteristics were analyzed. PBMCs were then irradiated with X-ray using a 6 MV linear accelerator at two radiation doses in the presence of nontoxic concentrations of MPEO-N nanoparticles (IC10). After 48 and 72 h of incubation, the radioprotective effect was investigated by measuring survival, apoptosis, and necrosis of PBMCs, using MTT assay and flow cytometry analysis.

KEY FINDINGS

The hydrodynamic diameter and zeta potential of nanoniosomes were 106.0 ± 4.69 nm and -15.2 ± 0.9 mV, respectively. The mean survival percentage of PBMCs showed a significant increase only at a radiation dose of 200 cGy compared with the control group. The percentages of apoptosis and necrosis of cells in the presence of MPEO-N nanoparticles at both radiation doses and incubation periods (48 and 72 h) demonstrated a significant reduction compared with the control.

CONCLUSION

MPEO-N nanoparticles as a natural antioxidant, exhibited a favorable radioprotective effect by a significant reduction in the percentage of apoptosis and necrosis of irradiated PBMCs.

The Use of Human, Bovine, and Camel Milk Albumins in Anticancer Complexes with Oleic Acid

Oleic acid (OA) is a monounsaturated fatty acid that upon binding to milk proteins, such as α-lactalbumin and lactoferrin, forms potent complexes, which exert selective anti-tumor activity against malignant cells but are nontoxic for healthy normal cells. We showed that the interaction of OA with albumins isolated from human, bovine, and camel milk results in the formation of complexes with high antitumor activity against Caco-2, HepG-2, PC-3, and MCF-7 tumor cells. The antitumor effect of the complexes is mostly due to the action of oleic acid, similar to the case of OA complexes with other proteins. Viability of tumor cells is inhibited by the albumin-OA complexes in a dose dependent manner, as evaluated by the MTT assay. Strong induction of apoptosis in tumor cells after their treatment with the complexes was monitored by flow cytometry, cell cycle analysis, nuclear staining, and DNA fragmentation methods. The complex of camel albumin with OA displayed the most pronounced anti-tumor effects in comparison with the complexes of OA with human and bovine albumins. Therefore, these results suggest that albumins have the potential to be used as efficient and low cost means of tumor treatment.

Ploidy and Proliferation Evaluated by Flow Cytometry. An Overview of Techniques and Impact in Oncology

Flow cytometric methods for the assessment of nuclear and chromosomal DNA content and of cell proliferation (including methods based on pulse-chase of bromodeoxyuridine and on monoclonal antibodies against nuclear oncoproteins and proliferation-associated antigens) are illustrated by examples and analyzed critically. The impact of most of these techniques for the study of human solid tumors, with exception of nuclear DNA content evaluation, appears still limited. In particular, new studies of cell lines and clinical material from human tumors using new proliferation markers and multiparameter flow cytometry are necessary to solve a considerable number of methodologic and scientific problems.

Evaluation of the selective toxic effect of the charge switchable diethyldithiocarbamate-loaded nanoparticles between hepatic normal and cancerous cells

Liver cancer is mainly originated by cancer stem cells (CSCs). Due to difference in pH between normal and tumor cell microenvironments, targeting hepatic CSCs exploiting pH-dependent charge switchable nanoparticles (NPs) is extremely required to limit nonselective toxicity to normal hepatocytes (NHCs) and to completely eliminate the root of cancer origin. In this study, NPs were prepared from cationic chitosan and then coated with anionic albumin namely uncoated and coated NPs, respectively. Both NPs were loaded with diethyldithiocarbamate (DDC) which is an inhibitor of the critical enzyme, aldehyde dehydrogenase (ALDH) 1A1, for CSCs survival. The charge switchable of coated DDC-loaded NPs in neutral and acidic pH (−19 and +28.5 mv, respectively) was illustrated. This special privilege of coated NPs mediated DDC releasing in a slightly acidic pH (tumor microenvironment) rather than a neutral pH (microenvironment of normal cells). Thence, these coated NPs showed the highest selective apoptosis-mediated toxicity only in murine hepatoma cells (Hepa) that may attribute to suppression of NF-κB expression and ALDH1A1 activity, subsequently collapsing 89.7% CD133⁺CSCs. These new findings declare that coated NPs could be promising safe selective anticancer drug for targeting hepatic CSCs and that requires additional future investigations using animal models of liver cancer.

DNA content in human colon cancer and non-neoplastic adjacent mucosa

DNA content was determined by flow cytometry in a series of 51 paired fresh tissue samples of primary colorectal carcinomas and the respective non-neoplastic adjacent mucosa in order to assess the relationship between DNA ploidy and the most commonly used prognostic factors. Aneuploidy was observed in 70.6% of the tumors and more than one aneuploid peak was present in 3.9%. Aneuploid tumor frequency was higher in left (93.3%) and right colon (64.7%) cancers than in rectal carcinomas (60.0%), and multiple aneuploid clones were detected more frequently in men than in women and in patients with advanced disease (Dukes stage D). Non-neoplastic mucosa adjacent to aneuploid tumors showed aneuploidy in 4 out of 51 samples (7.8%). The mucosa adjacent to diploid cancers had only diploid characteristics. Polidy did not correlate with histological abnormalities.

These findings suggest that DNA content as determined by flow cytometry needs further study with adequate follow-up to evaluate possible correlations with relapse-free and overall survival. Furthermore the aneuploidy of non-neoplastic mucosa provides evidence for a field defect in mucosa adjacent to colorectal cancer and supports the concept that this alteration may be of influence on carcinogenesis.

Efficiency of novel nanocombinations of bovine milk proteins (lactoperoxidase and lactoferrin) for combating different human cancer cell lines

Bovine lactoperoxidase (LPO) and lactoferrin (LF) are suitable proteins to be loaded or adsorbed to chitosan nanoparticles (NPs) for preparing stable nanoformulations with potent anticancer activity. In the present study, nanocombinations of LPO and LF revealed improvement in their stability and activity compared to single (free or nanoformulated) bovine proteins. The coating or loading of LPO-loaded NPs with LF resulted in the highest synergistic cytotoxicity effect against Caco-2, HepG-2, MCF-7 and PC-3 cells in comparison with other NPs and free proteins without causing toxicity toward normal cells. This synergistic improvement in the anticancer activity was apoptosis-dependent that was confirmed by severe alterations in cellular morphology, high percentage of annexin-stained cells and sub-G1 populations as well as nuclear staining with orange fluorescence of treated cancer cells. Additionally, significant alterations in the expression of well characterized cellular proliferation and apoptosis guards (NF-κB, Bcl-2 and p53) in these NPs-treated cancer cells compared to 5-fluorouracil (5-FU) treated cells. Our findings provide for the first time that these new synergistic nanoformulated forms of LPO and LF were superior in their selective apoptosis-mediating anticancer effect than free form of these proteins and 5-FU. LF coating or loading of LPO-loaded NPs present as promising therapy for cancer.

Divergent Anticancer Activity of Free and Formulated Camel Milk α-Lactalbumin

Alpha-lactalbumin (α-LA), a small milk calcium-binding globular protein, is known to possess noticeable anticancer activity, which is determined by the ability of this protein to form complexes with oleic acid (OA). To date, in addition to human and bovine α-LA, the ability to form such anti-tumor complexes with OA was described for goat and camel α-LA. Although the mechanisms of the anticancer activity of human and bovine α-LA are already well-studied, little is currently known about the anticancer action of this camel protein. The goal of this study was to fill this gap and to analyze the anticancer and pro-apoptotic activities of camel α-LA in its free form (α-cLA) and as an OA-containing complex (OA-α-cLA) using four human cancer cell lines, including Caco-2 colon cancer cells, PC-3 prostate cancer cells, HepG-2 hepatoma cells, and MCF-7 breast cancer cells as targets. The anti-tumor activities of OA-α-cLA and α-cLA were analyzed using MTT test, annexin/PI staining, cell cycle analysis, nuclear staining, and tyrosine kinase (TK) inhibition methods. We show here that the OA-α-cLA complex does not affect normal cells but has noticeable anti-cancer activity, especially against MCF-7 cells, thus boosting the anticancer activity of α-cLA and improving the selectivity of OA. The OA-α-cLA complex mediated cancer cell death via selective induction of apoptosis and cell-cycle arrest at lower IC₅₀ than that of free α-cLA by more than two folds. However, OA induced apoptosis at higher extent than OA-α-cLA and α-cLA. OA also caused unselective apoptosis-dependent cell death in both normal and cancer cells to a similar degree. The apoptosis and cell-cycle arresting effect of OA-α-cLA may be attributed to the TK inhibition activity of OA. Therefore, OA-α-cLA serves as efficient anticancer complex with two functional components, α-cLA and OA, possessing different activities. This study declared the effectiveness of OA-α-cLA complex as a promising entity with anticancer activity, and these formulated OA-camel protein complexes constitute an auspicious approach for cancer remedy, particularly for breast cancer.

Prognostic utility of chromosomal instability detected by fluorescence in situ hybridization in fine-needle aspirates from oral squamous cell carcinomas

BACKGROUND

Although chromosomal instability (CIN) has been detected in many kinds of human malignancies by means of various methods, there is no practical assessment for small clinical specimens. In this study, we evaluated CIN in fine-needle aspiration (FNA) biopsied oral squamous cell carcinomas (SCCs) using fluorescence in situ hybridization (FISH) analysis, and investigated its prognostic significance.

METHODS

To evaluate CIN status of tumors, FISH with genomic probes for the centromeres of chromosomes 7, 9, and 11 was performed on specimens obtained by FNA from 77 patients with primary oral SCCs.

RESULTS

High-grade CIN (CIN3) was observed in 11.7% (9/77) of patients with oral SCCs and was associated significantly with reduced disease-free survival (p = .008) and overall survival (p = .003). Multivariate Cox proportional hazards analysis showed that CIN status was significantly correlated with disease-free survival (p = .035) and overall survival (p = .041).

CONCLUSION

Analysis of CIN status using FISH on FNA biopsy specimens may be useful in predicting of recurrence and poor prognosis in patients with oral SCCs.

Aberrant crypt foci as precursors in colorectal cancer progression

Colorectal cancer progression originates when accumulated genetic and epigenetic alterations cause genomic instability and a malignant phenotype. Subsequent molecular pathway deregulation leads to histopathologic changes that are clinically evident as aberrant crypt foci (ACF) and visualized by high-magnification chromoscopic colonoscopy. ACF are biomarkers of increased colorectal cancer risk, particularly those with dysplastic features. Genetic profiling using genomic instability, loss of heterozygosity, and methylation analysis has revealed a minority population of ACF genotypically analogous to cancer.

Genomic instability in patients with non-small cell lung cancer assessed by the arbitrarily primed polymerase chain reaction

In the present study, we used DNA profiling to measure genomic instability in 22 patients with non-small cell lung cancer (NSCLC). Genomic instability was correlated with gender, the age of the patients at the time of diagnosis, the NSCLC subtype, histological grade and stage of the tumor, necrosis presence in the tumor and lymph node invasion. Genomic instability was significantly higher in patients older than 50 and those with adenocarcinoma compared to squamous-cell carcinoma. Most importantly, genomic instability significantly decreased as the tumor grade increased. Extensive genomic instability in the early carcinogenesis could be the prerequisite for NSCLC progression.

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.

Clinicopathological and biological features of DNA tetraploid colorectal cancers

PURPOSE

Most studies of colorectal cancers focus on a comparison of DNA diploid to non-diploid tumors consisting of tetraploid and aneuploid tumors. Tetraploid tumors alone have not been well studied. In the present study, clinicopathological and biological features of tetraploid colorectal cancers in contrast to those of diploid and aneuploid ones were investigated.

PATIENTS AND METHODS

DNA ploidy in 278 primary colorectal adenocarcinomas was determined by flow cytometry.

RESULTS

Among 278 cases, 8% of the cases were tetraploidy, 44% were aneuploidy, and 48% were diploidy. Compared to diploid tumors, tetraploid tumors were more frequent in advanced stage, high index of S-phase fraction and apoptosis, higher expression of Cox-2, c-erbB-2 and heat shock protein, but had decreased inflammatory infiltration (P<0.05). Compared to aneuploid tumors, tetraploid tumors had a high frequency of microsatellite instability, high expression of Cox-2 and heat shock protein (P<0.05). Unlike tetraploid tumors, aneuploid tumors had increased p53 expression but did not have microsatellite instability (P<0.05). Tetraploidy and aneploidy predicted a worse prognosis in the subgroups of stages A-C, proximal colon, p53 negative expression and higher S-phase fraction (P<0.05).

CONCLUSIONS

DNA tetraploid tumors seem, to some extent, to exhibit distinct characteristics of clinicopathology and biology compared with aneuploid or diploid colorectal cancers.

Relationship between genetic alterations and prognosis in sporadic colorectal cancer

Because chromosomal chromosomal instability (CIN) and microsatellite instability (MSI) are important genetic alterations in colorectal cancers, we classified the sporadic colorectal cancers (CRC) on the status of the CIN and MSI and explored their molecular profiles. A total of 213 colorectal tumors were collected for analysis of DNA ploidy, MSI, loss of heterozygosity (LOH), mutation of p53 (exons 5 to 9), Ki-ras (exons 1 and 2) and BRAF (V599E). Relationships between clinicopathological variables and molecular analyses were analyzed with the chi(2) test (Yates' correction). Kaplan-Meier survival curves were compared using log-rank test. Variables with p < 0.1 were entered into the Cox regression hazard model for multivariate analysis. High microsatellite instability (MSI-H) existed in 19 tumors (8.9%), which were more likely to be right-sided (31.6%) with poor differentiation (26.3%). Seventy-one (33.3%) tumors were diploid and 142 (66.7%) were aneuploid. Mutations in p53, Ki-ras and BRAF were found in 45.1%, 41.8% and 4.2% of tumors, respectively. Based on MSI, and CIN, 3 classes were defined: (i) High microsatellite instability MSI-H tumors: young age, high carcinoembryonic antigen (CEA) level, right colon, poorly differentiated, mucin production, high BRAF mutation, lower allelic loss and relatively good prognosis; (ii) Microsatellite stability (MSS) diploid tumors: right colon, poorly differentiated, less infiltrative tumor, mucin production, lower allelic loss and low p53, BRAF mutation; (iii) MSS aneuploid tumors: more infiltrative invasion, greater allelic loss and high p53 mutation. According to multivariate analysis, tumor stage and p53 mutation were significantly associated with disease progression. The MSS diploid and MSS aneuploid CRCs could be subtyped with p53 mutation and had different prognostic outcome and molecular profiles. The 4-year disease-free survival (DFS) of patients with MSS-diploid, wild-type p53 tumors was 67% and significantly higher than those of patients with MSS-diploid, mutant p53 CRC (30%, p = 0.003). The same trend was found in patients with MSS-aneuploid CRC(wild p53 vs. mutant p53, 64% vs. 41%, p = 0.009). We concluded that CIN, MSI and p53 mutation status might be used as a multiple parameter profile for the prognosis of sporadic colorectal cancer.

Loss of heterozygosity and DNA aneuploidy in colorectal adenocarcinoma

BACKGROUND

This study evaluated the relationship between DNA aneuploidy and loss of heterozygosity (LOH) at different genetic loci in colorectal adenocarcinoma.

METHODS

A total of 112 patients with surgically removed colorectal adenocarcinoma in Taipei Veterans General Hospital from January 1999 to July 2001 were included in this study. The pattern of DNA ploidy was determined with DNA flow cytometry, and the LOH of various genetic loci was determined with fluorescence polymerase chain reaction and denaturing gradient gel electrophoresis. The relationship between DNA ploidy, LOH of various genetic loci, and clinicopathologic variables was analyzed with the chi(2) test with Yates' correction as well as by multivariate binary logistic regression analysis.

RESULTS

Seventy-one (63.4%) of the 112 carcinomas had DNA aneuploidy. The DNA aneuploidy was not associated with any clinicopathologic variable. Ninety-one tumors (81.3%) exhibited LOH in at least one genetic locus. In the univariate analysis, the DNA aneuploidy was associated with LOH of Tp53-penta, D8S254, D5S346, and high-frequency LOH (P =.001, P =.016, P =.041, and P <.001, respectively). In the multivariate analysis, the most significant factor influencing DNA aneuploidy was D8S254, followed by Tp53-penta, high-frequency LOH, and D5S346.

CONCLUSIONS

DNA aneuploidy is strongly associated with LOH at specific genetic loci.

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.

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.

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.

DNA index as a significant predictor of recurrence in colorectal cancer

PURPOSE

To clarify the prognostic significance of the DNA content in cases of colorectal cancer, we investigated the relationship between the DNA content, as determined by the DNA ploidy or DNA index, and disease-free survival.

RESULTS

This study included 201 cases that were treated by curative surgery between 1989 and 1995 at our hospital. 68 were diploid and 133 were aneuploid. The mean DNA index of these tumors was 1.42. Recurrence occurred in 30 cases (14.9 percent). Tumor site, venous invasion, Dukes stage, DNA ploidy (diploid or aneuploid), and a DNA index (less than or greater than 1.4) correlated well with disease-free survival. A multivariable analysis suggested the DNA index to be a stronger predictor than DNA ploidy. Patients with aneuploid tumors had shorter disease-free survival than those with diploid tumors (P = 0.011), especially in Dukes Stage C cases (P = 0.0209). Patients with a DNA index greater than 1.4 also had a shorter disease-free survival than those with a DNA index less than 1.4 (P < 0.001), especially in Dukes Stage C cases (P = 0.0033).

CONCLUSIONS

The DNA index value (less than or greater than 1.4) seems to be a stronger predictor than DNA ploidy (diploid or aneuploid), and the combination of Dukes stage, tumor site, and a DNA index is, therefore, considered to be clinically valuable in predicting recurrence in cases of colorectal cancer.

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.

Flow cytometric DNA ploidy and S-phase fraction correlate with histopathologic indicators of tumor behavior in colorectal carcinoma

BACKGROUND

The clinical behavior of colorectal carcinoma is highly variable without reliable predictive biomarkers. Previous reports have shown that flow cytometric DNA analysis may provide valuable prognostic information in these tumors.

PURPOSE AND METHODS

This study evaluates the DNA ploidy and the S-phase fraction (SPF) on frozen samples obtained from 61 patients with colorectal carcinoma by using flow cytometry, and it correlates the data with histopathologic features known to affect disease prognosis. Tumors were classified using the World Health Organization's histologic criteria and were staged according the American Joint Committee on Cancer's classification system. Grade of the neoplasm, vascular invasion, and perineural tumor spread were evaluated in every case.

RESULTS

Fifty-nine percent of tumors were aneuploid and showed statistically significant higher S-phase values than diploid tumors (22.5 vs. 11.2 percent; P < 0.00001). Mean SPF of the whole series was 17.9 (range, 4.2-44.2) percent. A statistically significant association was found between SPF values and histologic grade (P < 0.0016), nodal status (P < 0.0007), distant metastasis (P < 0.0001), tumor stage (P < 0.0001), venous invasion (P < 0.0002), and lymphatic permeation (P < 0.01) but not with perineural growth and infiltration of the neoplasm through the bowel wall (T). DNA ploidy correlated positively with tumor stage (P < 0.03), and the association between aneuploidy and advanced stages of the disease was statistically significant.

CONCLUSIONS

These findings showed that flow cytometric DNA ploidy and SPF, evaluated in fresh samples, are potentially useful parameters to estimate colorectal carcinoma biopathology. Aneuploidy and high replicative neoplastic activity correlated with histopathologic features that are commonly associated with the prognosis of colorectal carcinoma, being SPF-related to disease dissemination and, therefore, an indicator of clinical relevance.

Genetic heterogeneity in sporadic colorectal adenomas

The majority of colorectal cancers develop from adenomatous polyps under the influence of factors that are still poorly understood. Tumourigenesis is generally considered a multistep process in which multiple genetic alterations occur, eventually reflected in abnormalities of the cellular DNA content. Macroscopical features such as tumour size and tumour architecture (tubular, tubulovillous, or villous) are correlated wit the chance of malignancy in the lesion. Grade of dysplasia can be considered an indicator for the level of progression of the adenoma towards invasive carcinoma. These characteristics were correlated with the presence or absence of K-ras mutations and the DNA ploidy in a prospective study performed on 46 large sporadic colorectal adenomas resected by endoscopy. DNA ploidy and K-ras mutations were analysed in two samples taken at distant sites in the adenomas. Aneuploidy was present in 12 adenomas (26 per cent) and K-ras mutations occurred in 26 (57 per cent). A highly significant correlation was found between aneuploidy and adenoma size, architecture, and grade of dysplasia. The presence of K-ras mutations was significantly correlated only with the size of the adenomas. The proportion of adenomas with aneuploidy and/or a K-ras mutation increased when two samples were analysed instead of one. This observation suggests that the prevalence of genetic mutations and of aneuploidy is probably underestimated, as generally only one sample is investigated. No correlation was observed between K-ras mutations and ploidy. This study demonstrates the presence of genetic heterogeneity in colorectal adenomas and supports the notion that K-ras mutation is an early event, while aneuploidy is a late event in the adenoma-carcinoma sequence.

The National Cancer Data Base. Report on colon cancer

BACKGROUND

Commission on Cancer data from the National Cancer Data Base (NCDB) report time trends in stage of disease, treatment patterns, and survival for patients with selected cancers. The most current data (1993) for patients with colon cancer are described.

METHODS

Five calls for data yielded 3,700,000 cases of cancer for the years 1985 through 1993 from hospital cancer registeries across the U.S., including 36,937 cases of colon cancer from 1988 and 44,812 from 1993.

RESULTS

Interesting trends are as follows: (1) the elderly ( > 80 years) present with earlier stage disease than younger patients; (2) the National Cancer Institute recognized cancer centers have more patients with advanced disease than other types of hospitals; (3) all ethnic groups have generally similar stages of disease at presentation, except for African-Americans who have a slightly higher incidence of Stage IV disease; (4) the proximal migration of the primary cancer continues with 54.7% of primary colon cancer arising in the right colon in 1993 compared with 50.9% in 1988; (5) an interaction between grade and stage of cancer seems present; and (6) patients with Stage III colon cancer who received adjuvant chemotherapy had a 5% improvement in 5-year relative survival.

CONCLUSIONS

The NCDB data are useful for reporting what cancer treatments are being administered and what outcomes are occurring in the U.S. The data suggest an important biologic role for grade of cancer. They also suggest that African-Americans and other ethnic groups have the same outcome as non-Hispanic whites but that access to medical care may still be less. Finally, the utility of adjuvant therapy for Stage III colon cancer may just be beginning to be appreciated.

Prognostic value of ploidy, cell proliferation kinetics, and conventional clinicopathologic criteria in patients with colorectal carcinoma: a prospective study

PURPOSE

The aim of this study was to obtain additional biologic determinants that may be of use in segregating into subgroups with different prognosis patients with similarly staged colorectal cancers.

METHODS

Between 1989 and 1991, a prospective study of prognostic factors has been performed in a group of 98 consecutive, unselected patients who underwent curative resections for primary untreated large bowel carcinoma. The fate of all patients is known at three years after operation. Clinical and pathologic data were recorded at the time of presentation and operation, and patients have been the subjects of regular follow-up. Tumor DNA content was determined by flow cytometry, and cell proliferative activity was determined by autoradiography with tritiated thymidine labeling index (LI).

RESULTS

Univariate analysis revealed that the most important predictors of survival (P < 0.001) were the presence of positive lymph nodes, the presence of preoperative complications, Dukes stage, and LI. The multivariate analysis showed that Dukes stage (P < 0.002) and LI (P < 0.0001) were the only factors significantly related to survival. Disease-free survival was influenced significantly by Dukes stage (P < 0.001), LI, according to the classification in the two groups of high and low proliferative activity, respectively, (P < 0.0001), LI, calculated as a continuous variable (P < 0.0002), and the presence of lymph node metastases (P < 0.003). Outcome (favorable/unfavorable) was influenced significantly by Dukes stage (P < 0.0001) and LI (P < 0.0001). Concordance for each patient between Dukes stage and outcome was 73.1 percent and between LI, calculated as a continuous variable, and outcome was 74.1 percent. If, on the other hand, Dukes stage and LI are used together, concordance with outcome reaches 89.2 percent.

CONCLUSION

We can conclude that, from a practical point of view, LI is an essential factor that must be combined with pathologic variables for a better prediction of patient outcome.

DNA flow-cytometric analysis in colorectal cancer: a comparison of metastasizing and non-metastasizing tumours

The most common cause of death in patients with colorectal cancer is metastatic liver disease. In order to identify patients at a high risk of developing hepatic secondaries from colorectal cancers, DNA content was measured in metastasizing colorectal primaries (Group I, n = 32) as well as in their subsequently resected liver secondaries and in sections of non-metastasizing colorectal cancers (Group II, n = 25). A modified interpretation system involving both a DNA index and percentage of cycling cells (those in S and G2 + M phases) was developed. DNA content was measured in paraffin-embedded sections by flow cytometry using internal controls (human peripheral blood mononuclear cells) and non-malignant tissue controls (19 patients with diverticular disease). In Group I there were significantly more tumours with both abnormal ploidy (aneuploid or abnormal tetraploid peak) and > 15% cycling cells compared with Group II (Chi-squared; P = 0.034). The combination of abnormal ploidy and > 15% cycling cells was superior to Dukes' classification for identifying metastasizing tumours (Logistic Regression; P = 0.047). However, it was not possible to discriminate between the two groups using either DNA ploidy or the percentage of cycling cells alone. The metastasizing colorectal cancers exhibited similar DNA ploidy characteristics and had a similar percentage of cycling cells compared with their liver metastases. These results suggest that tumour DNA ploidy plus the percentage of cycling cells may predict the development of liver metastases and thus survival in patients with colorectal cancer.

Sucrase-isomaltase is an independent prognostic marker for colorectal carcinoma

PURPOSE

Expression of disaccharidase sucrase-isomaltase (SI) is significantly enhanced during neoplastic transformation of colonic epithelium. Our study was designed to determine whether expression of SI within primary tumors was significantly associated with survival in patients with colorectal carcinoma (CRC).

METHODS

SI expression was analyzed by immunohistochemistry in paraffin sections from 182 Stage I to III CRC that had been resected for cure at the New England Deaconess Hospital between 1965 and 1977. Expression was scored as absent or present in 1 to 50 percent or more than 50 percent of tumor cells. Associations were explored among SI expression, other clinical or pathologic variables, and overall survival. The data set is mature, with 91 (56 percent) patients who had died of CRC at a median follow-up of 96 months.

RESULTS

Fifty-five percent of primary CRC expressed SI. When the multivariate Cox analysis was performed, nodal status, T stage, primary site, grade, and SI expression were independent covariates. SI expression was not associated with the expression of other clinicopathologic variables but increased the risk of death from colorectal carcinoma by 1.83-fold.

DISCUSSION

These results indicate that SI is a prognostic marker for CRC that is independent of stage-related variables in patients who have undergone potentially curative resections.

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.

Five-year prospective study of DNA tumor ploidy and colorectal cancer survival

BACKGROUND

Retrospective studies have suggested that DNA tumor content (ploidy) has a significant effect on survival. This group has reported, prospectively, that among patients who had colorectal resections for carcinoma, the 2-year tumor recurrence rate was significantly greater for patients with aneuploid tumor than for those with diploid tumors. This paper reports the 5-year survival rates of this cohort of patients.

METHODS

Three hundred sixty-three patients who had colorectal resections for cancer between November, 1982, and March, 1988, were studied prospectively. The DNA tumor ploidy was measured from fresh and paraffin embedded tissues. These patients were followed regularly in a dedicated colorectal clinic for a minimum of 5 years or until death. Of the 363 patients studied, 2 were lost to follow-up.

RESULTS

Forty percent of the tumors were diploid, the remainder aneuploid. The 5-year survival for patients who had curative resections was 76% for those with diploid tumors compared with 64% for aneuploid tumors (P = 0.05; Mantel-Cox, 3.7). On further analysis, the survival benefit conferred by a diploid tumor appeared to be confined to those with Stage B tumors. There was no relation between ploidy and sex, age of patient, stage, histologic grade, or site of tumor.

CONCLUSIONS

Ploidy is a useful objective measurement of the aggressiveness of Stage B tumors. Patients with aneuploid Stage B tumors have a poor prognosis; this group may benefit from adjuvant therapy.

Nuclear DNA content and nucleolar organizer regions in colorectal cancer

The prognostic value of nuclear DNA content and argyrophilic nucleolar organizer regions (AgNOR) is still controversial in colorectal cancer. Sixty patients with colorectal cancer were studied by flow cytometric DNA analysis and AgNOR measurement, and their prognostic significance was tested. DNA index was closely linked to depth of invasion and lymph node metastasis, while AgNOR count did not correlate with such parameters. The survival curve was strongly influenced by depth of invasion, lymph node metastasis, and Dukes' stage but was not affected by DNA ploidy and AgNOR count. These results indicate that neither DNA ploidy nor AgNOR count correlates with survival of patients, although DNA ploidy is linked to progression of colorectal cancer.

DNA index and S phase fraction in uveal malignant melanomas

AIMS

To predict 5 year survival in patients with uveal malignant melanomas DNA indices were studied.

METHODS

Using 45 paraffin embedded uveal malignant melanomas, the DNA index and S phase fraction of each tumour were the predictor variables recorded.

RESULTS

Using the Cox proportional hazards model, aneuploid tumours and tumours which had an S phase fraction greater than 4% were significant predictors of early death. In order to demonstrate a biological gradient between a larger DNA index and shorter survival time, linear regression and transformed linear regression models were used. However, no such gradient could be demonstrated.

CONCLUSION

Although this study shows promise for the use of DNA studies in the prognosis of uveal malignant melanoma, the exact role of these techniques remains to be determined.

Comparison of double and single parameters in DNA analysis for staging and as a prognostic indicator in patients with colon and rectal carcinoma

PURPOSE

This study was designed to determine the reliability of DNA analysis in predicting outcome of patients with colorectal carcinoma and compare the prognostic efficacy of DNA analysis using two parameters vs. a single parameter.

METHODS

Two hundred forty-eight patients with colon and rectal carcinoma were entered in the study over a period of 84 months. Thirty-one percent of carcinomas were found in the rectum. A total of 23.6 percent of cancers were found in the sigmoid colon. Majority of the patients were 60 years or older. Male to female ratio was equal. The colon bearing carcinoma was sent in a fresh state after resection for flow cytometry and DNA analysis. In this study, analysis was made, comparing two parameters (aneuploidy and S-phase fraction over 20 percent) with single parameters (aneuploidy) for staging and as a prognostic indicator in patients with colon and rectal carcinoma.

RESULTS

The combined presence of aneuploidy and S-phase fraction over 20 indicated a poorer prognosis in patients with colon and rectal carcinoma. The prediction of patient outcome was more accurate with DNA analysis using two parameters than using a single parameter alone (P value = 0.00003).

CONCLUSION

In our analysis, the odds of survival are over 3.7 times greater for aneuploidy than aneuploidy plus S-phase fraction over 20 percent.

Allelic loss of chromosome 18q and prognosis in colorectal cancer

BACKGROUND

Colorectal cancer occurs in approximately 150,000 people each year in the United States. Prognostic assessment influences the treatment of patients with colorectal cancer, including decisions about adjuvant therapy. We evaluated chromosome 18q allelic loss, a genetic event associated with tumor progression, as a prognostic marker for this disease.

METHODS

We developed procedures to examine the status of chromosome 18q with microsatellite markers and DNA from formalin-fixed, paraffin-embedded tumors. Allelic loss of chromosome 18q was assessed in 145 consecutively resected stage II or III colorectal carcinomas.

RESULTS

Among patients with stage II disease, the five-year survival rate was 93 percent in those whose tumor had no evidence of allelic loss of chromosome 18q and 54 percent in those with allelic loss; among patients with stage III disease, survival was 52 and 38 percent, respectively. The overall estimated hazard ratio for death in patients whose tumor had chromosome 18q allelic loss was 2.83 (P = 0.008) according to univariate analysis. Furthermore, chromosome 18q allelic loss remained a strong predictive factor (hazard ratio for death, 2.46; 95 percent confidence interval, 1.06 to 5.71; P = 0.036) after adjustment for all other evaluated factors, including tumor differentiation, vein invasion, and TNM stage.

CONCLUSIONS

The status of chromosome 18q has strong prognostic value in patients with stage II colorectal cancer. The prognosis in patients with stage II cancer and chromosome 18q allelic loss is similar to that in patients with stage III cancer, who are thought to benefit from adjuvant therapy. In contrast, patients with stage II disease who do not have chromosome 18q allelic loss in their tumor have a survival rate similar to that of patients with stage I disease and may not require additional therapy.

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.

Prognostic value of DNA analysis in colorectal carcinoma

BACKGROUND

Reported experiences regarding the prognostic significance of DNA content in colorectal carcinoma have been a matter of controversy.

METHODS

DNA analysis with image cytometry was performed in 137 patients with colorectal cancer. Only patients who had resection without tumor residual and who did not die postoperatively as a consequence of the operation were entered in the study. At the time of DNA analysis, neither the histomorphologic data nor the relapse-free survival time of the patients were known.

RESULTS

In this investigation the DNA content of tumor cells had no univariate or multivariate influence on the relapse-free survival time. The prognosis was dependent on the tumor localization, depth of tumor infiltration, lymph node metastasis, and grade.

CONCLUSIONS

DNA content provides no additional prognostic information in colorectal carcinoma.

DNA densitometry of colorectal cancer

DNA analysis was assessed by densitometry for 281 cases of colorectal adenocarcinoma. Detection of aneuploidy in a single case rose from 65% if one, to 92.5% when three or more sections, were analysed. Although aneuploid tumours had significantly larger nuclear areas than near diploid tumours (p = 0.009), densitometric measurements showed no association with clinicopathological variables. DNA content determined by densitometry was compared with that from flow cytometry on 465 tissue sections from 241 cases. Aneuploidy assessed by flow cytometry was significantly associated with that determined by densitometry (p < 0.01 for all comparisons), ploidy state being similar in 381 sections (82%, kappa = 0.63, p < 0.001), and 187 cases (77.6%, kappa = 0.57, p < 0.001). Univariate survival analysis showed that DNA densitometric variables had no significant association with survival in (a) all cases, (b) cases without lymph node metastases, or (c) cases without distant metastases. Multivariate regression analysis of densitometric and clinicopathological variables identified Dukes's stage, patient age, and tumour differentiation as the combination of variables most closely related to survival. Densitometric measurement of DNA content could not significantly improve on the prognostic model containing these three variables. It is concluded that, although the assessment of DNA content by densitometry is comparable with that of flow cytometry, conventional histological variables remain the best predictors of prognosis in colorectal cancer.

Prognostic significance of flow cytometric analysis of DNA content in colorectal cancer: a prospective study

We prospectively analyzed the tumor DNA content by flow cytometry in 100 patients who underwent a curative resection for colorectal cancer between August 1989 and May 1992 in order to evaluate the prognostic significance of DNA ploidy and the DNA index (DI). Patients with aneuploid tumors were found to have a significantly shorter disease-free survival than those with diploid tumors (P = 0.014). In addition, patients who had tumors with a DI greater than 1.6 had a significantly shorter disease-free survival than those who had tumors with a DI of less than 1.6 (P = 0.0001). After stratification by stage, this association was only seen in Dukes' stage C disease (P = 0.0065). Cox's regression analysis demonstrated that the DI (below or above 1.6) rather than DNA ploidy was an important independent predictor of disease-free survival. These results suggest that the DI rather than DNA ploidy provides us with important prognostic information in patients undergoing curative surgery for colorectal cancer.

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.

Poor prognosis associated with elevated serum CA 19-9 level in advanced colorectal carcinoma, independent of DNA ploidy or SPF

DNA ploidy, S-phase fraction (SPF) for the tumours, serum tumour markers such as carcinoembryonic antigen (CEA) and serum CA 19-9 and major clinical parameters were analysed as prognostic factors in 105 patients with advanced colorectal carcinoma. All 105 were treated with a three-drug schedule including low dose epirubicin and sequential methotrexate, 5-fluorouracil, followed by leucovorin rescue. In univariate analysis, gender, Karnofsky index, extent of metastases, presence of abdominal metastases, CEA and CA 19-9 correlated with survival. Age, presence of liver or of lung metastases, DNA ploidy or SPF were not significantly associated with survival. In stepwise multivariate analysis an elevated serum CA 19-9 level, a poor Karnofsky index and multiple sites of metastases were independent adverse prognostic factors. Based on the multivariate analysis, patients were grouped in three categories. Group 1 consisted of 32 patients with Karnofsky > or = 80, with a normal serum CA 19-9 level and a single site of metastases. Group 2 consisted of 48 patients with Karnofsky > or = 80 and with an elevated serum CA 19-9 level or multiple sites of metastases. Group 3 consisted of 14 patients with Karnofsky < or = 70. This classification gave a highly significant correlation with survival (chi 2 = 45.52, P < 0.001, log rank test). The median survival in group 1, group 2 and group 3 was 30.1 months, 13.5 months and 3.9 months, respectively. Based on these results we suggest that trials involving advanced colorectal cancer should include the measurement of serum CA 19-9 levels as one of the most important prognostic factors, but also include documentation of other independent prognostic factors.

Prognostic factors in colorectal cancer

The prognostic power of the extent of tumour invasion is indisputable; Dukes' classification has repeatedly been proven to be strongly correlated with patient survival. Modifications have led only to confusion, resulting in caution being required in the classification of patients with Dukes' A tumours. In the UK, the American tumour node metastasis and Australian clinicopathological systems are frequently considered too complex for routine clinical use. Meanwhile, Jass's classification may be complicated by observer variation between pathologists, and recent evidence suggests that it offers no advantage over that of Dukes. All the conventional staging systems also fail to take the skill of the surgeon into account when determining outcome. Attempts at quantifying tumour structure have not heralded the expected major advance. For instance, the expense and uncertain prognostic value of tumour DNA content assessed by flow cytometry are likely to restrict widespread use of this technique. It may soon be possible, however, to provide optimum treatment for patients based on individual tumour doubling times. Classification using knowledge of how a small number of cells in the tumour have the ability to invade locally, enter blood vessels and metastasize would also provide important prognostic information on which treatment could be based. Until then, the ease of use and high prognostic power of Dukes' classification ensure that, after 60 years, it is still the 'gold standard' against which all other prognostic classifications in colorectal cancer should be assessed.

The relationship of DNA aneuploidy to molecular genetic alterations in colorectal carcinoma

Altered total nuclear DNA content is frequent in colorectal carcinomas, but the mechanisms producing aneuploidy are unknown. Therefore, DNA ploidy by flow cytometry was correlated with molecular genetic alterations and tumor characteristics in 50 colorectal carcinomas. The prognostic value of these alterations was also evaluated because aneuploidy has been associated with poor prognosis. Thirty-nine of the carcinomas (78%) were DNA aneuploid. When compared with diploid carcinomas, aneuploid tumors had greater mean fractional allelic loss, defined as the fraction of evaluable nonacrocentric autosomal arms with deletion (0.25 +/- 0.15, range 0-0.667, vs. 0.12 +/- 0.10, range 0-0.345; P = 0.006). DNA index by flow cytometry correlated with fractional allelic loss (r = 0.38, P = 0.006). Aneuploid tumors also had more frequent allelic loss on chromosome 17p (87% vs. 55%; P = 0.017), but less frequent ras gene mutation (44% vs. 82%; P = 0.025). Among the 25 right-sided and 25 left-sided tumors, DNA diploid tumors were more frequent on the right side (P = 0.002), whereas deletion of 17p was found predominantly on the left side. Aneuploidy was associated with moderate and poor differentiation of the carcinomas but not with distant metastasis. By contrast, high fractional allelic loss, deletion of 17p, and deletion of 18q were associated with distant metastasis. In survival analysis of patients with Dukes' B or C carcinoma, DNA aneuploidy was not a significant discriminator, but patients whose tumor had deletion of 17p or deletion of both 17p and 18q had poorer survival (P = 0.045 and 0.022, respectively). The results suggest that DNA aneuploidy is associated with some of the molecular genetic alterations and phenotypic characteristics of colorectal carcinomas but is not a reliable indicator of metastatic potential.

Autoradiographic and flow-cytometric assessment of cell proliferation in primary colorectal cancer: relationship to DNA ploidy and clinico-pathological features

Two cell-kinetic parameters, the [3H]thymidine-labeling index [3H]dT LI and the flow-cytometric S-phase cell fraction (FCM-S), and DNA ploidy were determined for a prospective series of 110 primary colorectal cancers. Aneuploidy was observed in 66% of tumors and more than one aneuploid peak was present in 12%. The frequency of aneuploid tumors was higher in rectal (80%) and left-colon (70%) cancers than in right-colon cancers (51%), and multiple aneuploid clones were detected more frequently in men than in women (p = 0.03) and more frequently in advanced Dukes' D-stage patients (p = 0.08). The median [3H]dT LI value (17.4%) was similar to the FCM-S value determined by a planimetric model (16.2%) and somewhat higher than the FMC-S value obtained by an optimization procedure (11.2%). However, there was no significant relationship between the [3H]dT LI value and either FCM-S value for individual tumors. Moreover, FCM-S values were higher in aneuploid than in diploid tumors, whereas [3H]dT LI values were independent of DNA-ploidy status; [3H]dT LI and FCM-S were also related differently to some clinical and pathological features such as tumor site and histology. These findings suggest different biological meanings for these 2 cell-kinetic parameters, which should not be used interchangeably.

Hereditary nonpolyposis colorectal cancer (Lynch syndrome II). Diploid malignancies with prolonged survival

DNA flow cytometry was performed on 44 paraffin blocks from 16 specimens of 11 lesions in five patients from two families identified as probably having the dominant gene of the Lynch Type II syndrome. All but one specimen showed diploidy, although two such specimens were metastases and one a recurrence. The one aneuploid gastric biopsy was followed by a resection with diploidy in all 13 blocks from the malignancy and may represent a superficial change without clinical significance. The prolonged survival after discovery of malignancy in such families may be explained in part by diploidy of the lesions.

Clinical and pathologic prognostic indicators in colorectal cancer. A population-based study

The institution of a colorectal Cancer Register in a health care district of Northern Italy gave the authors the opportunity to evaluate the prognostic relevance of several morphologic and clinical variables by univariate and multivariate analyses. Of the 134 patients registered in 1984, 132 were followed up until the end of 1989. Overall 5-year survival was 37%, but the figure increased to 43% when only colorectal cancer-related deaths were considered. Univariate analysis for clinical variables showed that TNM staging and age at diagnosis were significantly related to prognosis, whereas none of the other parameters were indicative of the clinical outcome. With a similar analysis, among the various morphologic variables, pattern of growth (infiltrating versus expanding) and extent of fibrosis (extensive versus little or absent) appeared to be indicators of prognosis. When the variables that were significant (stage, age, pattern of growth, and fibrosis) in the univariate analysis were entered into the Cox model of multivariate analysis, TNM staging was the only parameter that maintained an independent prognostic importance. The authors state that their results confirm the importance of stage in predicting survival for cancer of the large bowel and suggest that the possible prognostic value of clinical and morphologic variables should be investigated within each of the major TNM or Dukes' classes.