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Biomedical subjects

M Ponz de Leon

Publications and source records attributed to M Ponz de Leon.

At least 19 recordsLinked to original sources
PubMed1996

Frequency and clinical features of multiple tumors of the large bowel in the general population and in patients with hereditary colorectal carcinoma.

BACKGROUND: Reports on the frequency of multiple carcinomas of the colon and rectum have varied from 3-4% to more than 10% of all tumors of the large bowel. METHODS: We reviewed the files of a specialized colorectal cancer registry with the following objectives: a) to determine the frequency of multiple tumors (synchronous or metachronous) in the general population; b) to compare these values with those observed in patients with hereditary nonpolyposis colorectal carcinoma (HNPCC); and c) to evaluate the clinical outcome of patients with multiple tumors and the role of other clinical parameters in the development of these neoplasms. RESULTS: From 1984 to 1992, 53 patients with multiple tumors (of 1298 registered patients, 4%) had large bowel carcinoma; 33 (2.5%) were synchronous and 20 (1.5%) metachronous. The total number of multiple colorectal carcinomas was 95, which was 7% of all registered colorectal carcinomas (1337 carcinomas in 1298 patients). Multiple tumors occurred significantly more often in patients with HNPCC than in those with sporadic carcinomas (P < 0.001); this increased prevalence was more marked for metachronous lesions, which occurred almost 4 times more often in patients with HNPCC (5.8% vs. 1.3%; P < 0.001). The average interval of time between the first and the second malignancy was 8.7 years; there was no significant difference between hereditary and sporadic tumors. Patients with synchronous tumors did not show appreciable differences in survival when compared with individuals who had single neoplasms. In contrast, a poor clinical outcome was observed in patients with metachronous tumors after the development of the second carcinoma. Finally, polypoid adenomas of the large bowel were found significantly more often in patients with multiple primary tumors than in those with a single tumor. CONCLUSIONS: These results emphasize the importance of preoperative pancolonoscopy for the identification of possible synchronous tumors (both benign and malignant) and long-lasting endoscopic follow-up for the detection of recurrent or metachronous lesions. The conclusions are even more pertinent for patients with HNPCC, whose risk of metachronous tumors is significantly higher than that of patients with sporadic carcinoma.

Aged↗
PubMed1996

Survival for colon and rectal cancer in a population-based cancer registry.

Dukes' stage is the most powerful indicator of patient outcome for colorectal cancer. Several cancer survival studies have considered other prognostic variables, but results are often conflicting. We sought to assess the independent value of several clinical and morphological variables in defining colorectal cancer specific survival. 397 colorectal cancer patients diagnosed from 1984 to 1986, and registered in a large bowel cancer registry instituted in a local health district of Northern Italy, were actively followed-up until 31 December 1991. Univariate and multivariate survival analyses were carried out in colon and rectal cancer cases, separately, using the actuarial life-table method and Cox proportional hazard regressions. Crude and specific 5-year survival rates were 37.5 and 41.4%. In univariate analysis, TNM (tumour, nodes and metastases) stage was the strongest predictor of prognosis in both sites. Other variables significantly related to survival were age of patient at diagnosis and pattern of tumour growth in colon cancer, type of differentiation and pattern of tumour growth in rectal cancer. In multivariate analyses, after adjusting for stage, age had a weak but significant negative effect on colon cancer survival, whereas rectal tumours with the infiltrating type of growth had a significantly worse prognosis than those with the expanding type. Colorectal cancer survival should be analysed in the main large bowel subsites in order to define high-risk groups within each TNM stage category.

Aged↗
PubMed1995

Familial aggregation of tumors and detection of hereditary non-polyposis colorectal cancer in 3-year experience of 2 population-based colorectal-cancer registries.

The clinical data of 2 population-based registries, located in areas with different incidence rates of colorectal cancer, were used in order to assess the role of familial factors in the pathogenesis of these tumors. The occurrence of tumors in family members was investigated in 389 subjects with colorectal cancer registered in Modena (Northern Italy, an area characterized by a high incidence of colorectal malignancies) between 1984 and 1986; similar information was obtained in 213 patients with tumors of the large bowel registered in Ragusa (Sicily, Southern Italy, an area of similar magnitude and with low incidence rates for these tumors) in the 3-year period 1988 to 1990. In both series, colorectal cancer occurred significantly more often among relatives of patients. Controls were patients of the same sex and age (+/- 5 years) hospitalized during the study periods, but not for gastrointestinal or neoplastic diseases. There were 89 cancer cases (3.1%) among 2,851 relatives of patients in Modena, vs. 17 cases among 1,744 relatives (1.0%) in Ragusa (p < 0.01). Apart from colorectal cancer, there was no excess of other types of tumors in patients' families (in both series). During the 3 years of registration, 17 cases of hereditary non-polyposis colorectal cancer (HNPCC, or Lynch syndrome) were diagnosed in Modena; in contrast, this syndrome was more rare in Ragusa (one case only during 3 years of observation). Similarly, many more families with clinical suspicion of HNPCC were recorded in Northern regions (44 vs. 10). Although incidence rates of colorectal cancer are appreciably higher in Northern than in Southern Italian regions, the excess of this cancer type among close relatives is similar. However, full-blown HNPCC or suspected Lynch syndrome were significantly more frequent in Northern Italy.

Aged↗
PubMed1995

First observation of microadenomas in the ileal mucosa of patients with familial adenomatous polyposis and colectomies.

BACKGROUND & AIMS: Little data are available on the type and prevalence of mucosal changes involved in the development of ileal adenomas in patients with familial adenomatous polyposis who have undergone colectomy. However, colonic metaplasia of the ileal epithelium is thought to be an important step in the development of such adenomas. METHODS: Retrograde endoscopy and biopsy of the distal ileum were performed in 17 affected patients who underwent total colectomy or proctocolectomy 3-184.1 months (mean, 80.3 +/- 13.9 months) before the study. RESULTS: Macroscopic ileal polyps were identified in 14 (82.4%) patients. All polyps were sessile and 1-5 mm in size. Histological analysis showed adenomas in 9 (52.9%) patients and lymphoid hyperplasia or inflammation in the others. In 1 patient, an area of colonic-type metaplasia of the ileal mucosa was found close to an adenoma. However, in 5 (29.4%) patients, random biopsy specimens of the normal-appearing mucosa showed foci of abnormal crypts in the absence of metaplasia, with histological appearance similar to the findings described in dysplastic aberrant crypt foci of the colon. Such lesions, previously observed only in colorectal mucosa and referred to as microadenomas or oligocryptal adenomas, are considered putative preneoplastic abnormalities. CONCLUSIONS: Although the hypothesized sequence normal ileal mucosa leading to colonic-type metaplasia leading to adenoma cannot be excluded, our findings support the sequence normal ileal mucosa leading to microadenoma leading to gross adenoma and possibly cancer as the main histogenetic pathway, as already suggested for the large bowel.

Adenoma↗
PubMed1995

The effect of family size on estimates of the frequency of hereditary non-polyposis colorectal cancer.

Diagnosis of hereditary non-polyposis colorectal cancer (HNPCC) is currently based on phenotypical analysis of an expanded pedigree. Diagnostic guidelines ('Amsterdam criteria') proposed by the International Collaborative Group on HNPCC are often too stringent for use with small families. There is also the possibility of false-positive diagnosis in large pedigrees that may contain chance clusters of tumours. This study was conducted to determine the effect of family size on the probability of diagnosing HNPCC according to the Amsterdam criteria. A total of 1052 patients with colorectal cancer were classified as HNPCC or non-HNPCC according to the Amsterdam criteria. Associations between this diagnosis and the size of the first-degree pedigree were evaluated in logistic regression and linear discriminant analyses. Logistic regression showed a significant association for family size with the Amsterdam-criteria-based HNPCC diagnosis. Linear discriminant analysis showed that HNPCC diagnosis was most likely to occur when first-degree pedigrees contained more than seven relatives. Failure to consider family size in phenotypic diagnosis of HNPCC can lead to both under- and overestimation of the frequency of this disease. Small pedigrees must be expanded to reliably exclude HNPCC. Positive diagnoses based on assessment of eight or more first-degree relatives should be supported by other clinical features.

Adult↗
PubMed1995

Biologic characterization of hereditary non-polyposis colorectal cancer. Nuclear ploidy, AgNOR count, microvessel distribution, oncogene expression, and grade-related parameters.

The identification of hereditary non-polyposis colorectal cancer (HNPCC) is important not only for the patient, but also for family members who are at increased risk of developing cancer. To determine if measuring various pathobiologic features of the colon carcinomas is useful in separating sporadic from HNPCC tumors, the authors studied tumor tissues from 46 patients with HNPCC and compared them to 70 with sporadic colorectal carcinoma. Parameters investigated included DNA ploidy (flow cytometry), AgNOR count (by silver staining), microvessel density (immunohistochemistry), p53 and K-ras expression, and grade-related parameters. Diploid tumors were more frequent in patients with HNPCC (65% vs 40%, P < .02), thus confirming previous observations concerning such an association. Higher AgNOR counts and greater AgNOR areas were observed in sporadic tumors than in HNPCC (5.2 +/- 1.5 vs 4.5 +/- 1.8, P < .01). Hereditary tumors tended to be less vascularized, whereas oncogene expression and grade-related parameters did not show appreciable differences between the two types of tumors. In conclusion, some of the investigated parameters may contribute to defining the biologic profile of HNPCC. In addition, these findings support the clinical impression of a more favorable outcome that is frequently seen in HNPCC patients.

Adult↗
PubMed1995

Argyrophilic nucleolar organizer regions and bromodeoxyuridine and 3[H]-thymidine labelling indices in colorectal cancer.

The count of argyrophilic nucleolar organizer regions (AgNORs) has been proposed as a useful method for evaluating cell replication in human tumours. The current study was undertaken to compare AgNOR values in colorectal cancers with two better established methods for investigating cell proliferation such as bromodeoxyuridine (BrdUrd) and 3[H]-thymidine (3[H]dT) labelling indices (LIs). Because some concern still exists regarding accuracy and reproducibility of AgNOR quantifying methods, we carried out a control study by independently repeating the same measurements (number, area and area per silver-stained NOR particle) in two centres with different operators and computer-assisted image analysers on 40 colorectal carcinomas. AgNOR values recorded in the two centres were strictly correlated (r = 0.75; P < 0.001 for number; r = 0.62, P < 0.01 for area; r = 0.63, P < 0.001 for area per silver-stained NOR particle) and the range of values were almost identical. Then, AgNOR values were compared with BrdUrd and 3[H]dT LIs, respectively obtained by in vivo incorporation and in vitro incubation in the same series of colorectal carcinomas. No correlation was found between AgNOR values and BrdUrd or 3[H]dT LIs. BrdUrd and 3[H]dT LIs were instead reciprocally significantly correlated. No evident correlation was seen between LIs or AgNOR values and clinico-pathological parameters of the tumour. In conclusion, in colorectal neoplasms, AgNOR values did not appear to relate with more direct parameters of cell proliferation. It follows that AgNOR reliability as a biomarker of cell proliferation remains questionable.

Adult↗
PubMed1994

Role of clinical criteria in the diagnosis of hereditary non-polyposis colorectal cancer (HNPCC): results of a multivariate analysis.

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant disease characterized by early-onset colorectal tumors, primarily in the right colon, that are frequently associated with other cancers. In the absence of a reliable biomarker, clinical criteria for diagnosing HNPCC have been proposed by the International Collaborative Group on HNPCC (ICG-HNPCC). However, these criteria are often too restrictive for application in small families. We analyzed 6 clinical/pathological features suggestive of genetic colon-cancer risk in 970 colorectal-cancer patients defined according to the ICG criteria as HNPCC (96) or non-HNPCC (874). Logistic regression analysis was used to determine their relative potentials for predicting the diagnosis of HNPCC. The most predictive were then used to estimate HNPCC risk levels within the non-HNPCC group. Multivariate analysis showed the following associations with HNPCC diagnosis: vertically transmitted cancer ("highly predictive"), early-onset (< 50 yrs) colorectal cancer, aggregation of tumors in the nuclear pedigree and proximal-colon tumors (the last 3 considered "predictive"). Re-evaluation of all families revealed that 76 non-HNPCC families (8.9% of the whole series) satisfied our highly predictive vertical-transmission criterion plus at least one of the other "predictive" criteria. The presence of 2 consecutive generations affected by colorectal cancer or early primaries seems to be a major risk indicator of hereditary colorectal cancer. Using this approach we identified a large group of families that require further evaluation, although they do not currently meet the ICG-HNPCC criteria for HNPCC.

Colorectal Neoplasms, Hereditary Nonpolyposis↗