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Biomedical subjects

P S Prabhakaran

Publications and source records attributed to P S Prabhakaran.

9 recordsLinked to original sources

Submandibular synovial sarcoma with t(X;18) and synovial sarcoma of the toe with additional cytogenetic abnormalities: presentation of two cases and review of the literature.

We report cytogenetic findings from fine-needle aspiration samples of two synovial sarcoma patients. The cases are of interest because (1) one case is of a rare site (submandibular region) of the head and neck, and (2) the other is a patient with synovial sarcoma of the toe showing additional cytogenetic abnormalities along with t(X;18). The literature of this tumor is reviewed.

Adult↗

Cytogenetic characterization of Ewing tumors using fine needle aspiration samples. a 10-year experience and review of the literature.

Chromosomal analysis was performed in fine needle aspiration samples of 98 primary Ewing tumors (ETs) prior to treatment. Among the 58 (59.18%) successful cultures, t(11;22)(q24;q12) was observed in 87.9% and 6.8% had abnormalities other than t(11;22), viz., del(22)(q12), der(16)t(1;16)(q12;q11), and variant t(8;22)(q24;q12). Involvement of breakpoints 1q21, 1q22, 3p14, 16q22, and 17p13 was also observed. Numerical abnormalities such as trisomies 8 and 12 were found in 29.3% and 20.6% and trisomy 18 in 17.2%. An attempt was made to evaluate the role of these additional changes in the process of tumor development, metastasis, and progression of the disease. This is the largest cytogenetic study on ET from a single center using a simple and reliable technique of fine-needle aspiration culture. The literature on cytogenetics of ET is reviewed.

Adolescent↗

Sacral chordomas: a 10-year study.

A retrospective analysis of 14 cases of sacral chordoma seen between 1984 and 1993 at the Kidwai Memorial Institute of Oncology is reported. The mean patient age was 54 years, with 13 males and one female. Seventy-one per cent of patients presented with symptoms related to a painful sacral mass. Eight patients underwent radical surgery and two had adjuvant radiotherapy. One patient had a partial tumour resection. Three patients received radical radiotherapy. Two patients were offered only pain relief medication. The median follow-up was 33 months. The actuarial overall survival (OS) at 5 years was 48%. In the 12 patients in whom curative therapy was attempted, the 5-year OS was 56% and progression-free survival was 36%. Four patients developed local recurrence and three developed distant metastasis.

Chordoma↗

Importance of anatomical subsite in correlating risk factors in cancer of the oesophagus--report of a case--control study.

In Bangalore, cancer of the oesophagus is the third most common cancer in males and fourth most common in females with average annual age-adjusted incidence rates of 8.2 and 8.9 per 100,000 respectively. A case-control investigation of cancer of the oesophagus was conducted based on the Population-based cancer registry, Bangalore, India. Three hundred and forty-three cases of cancer of the oesophagus were age and sex matched with twice the number of controls from the same area, but with no evidence of cancer. Chewing with or without tobacco was a significant risk factor. In both sexes chewing was not a risk factor for cancer of the upper third of the oesophagus. Among males, non-tobacco chewing was a significant risk factor for the middle third but not for the other two segments and tobacco chewing was a significant risk factor for the lower third of the oesophagus, but not for the other two segments. Bidi smoking in males was a significant risk factor for all three segments being highest for the upper third, less for the middle third and still less for the lower third. The risk of oesophageal cancer associated with alcohol drinking was significant only for the middle third.

Case-Control Studies↗

Hemangiopericytoma of bone--a case report.

A case of low grade hemangiopericytoma of three years duration occurring in the upper end of the femur of a 70 year old man is described. Radiologically, the upper third of the right femur showed a destructive expansile osteolytic lesion with soft tissue extension. The tumour was partially encapsulated. Mitoses were 0-1 per 10 high power fields, suggesting the low grade malignant nature of the lesion. It is felt that all hemangiopericytomas occurring in bone should be considered biologically malignant.

Aged↗

Unusual splenic metastasis from oesophageal cancer.

The most common visceral metastasis from oesophageal carcinomas are lungs and liver. A case of splenic metastasis from a squamous carcinoma of oesophagus is reported. To our knowledge, splenic metastasis without any nodal disease has not been described previously. The pattern of reported metastasis is summarised.

Carcinoma, Squamous Cell↗

Neoadjuvant Cis-DDP in esophageal cancers: an experience at a regional cancer centre, India.

We are analysing the results of 80 patients who underwent surgery during 1983-84 for esophageal cancer. Forty patients who received pre-operative single agent Cis-DDP were grouped under "A" and 40 patients who went for surgery directly were grouped under "B". Twenty-two patients (55%) of Group A showed tumor necrosis. Both groups underwent resection and hand-sewn anastamosis of the esophagus. There were 10 post-operative deaths among 80 resected cases, 9 of them being from anastomatic leak. Cis-DDP has induced negligible side effects. A comparatively high survival rate during early years in patients who responded to Cis-DDP suggests that neoadjuvant chemotherapy might be of value.

Cisplatin↗

Biologic factors and response to radiotherapy in carcinoma of the cervix.

Ionizing radiation has been used to treat cancers for a century. However, radioresistance remains a major problem in the clinic. Recent advances in the understanding of the molecular events that occur following ionizing radiation leading to DNA damage and repair, apoptosis, and cell cycle arrests suggest new ways in which the radiation response might be manipulated. Seventy-eight cases of carcinoma of the cervix of the same stage (II A and B) were analyzed retrospectively. All patients were treated with radiotherapy (RT) with a dose varying from 35 Gy to 50 Gy with 200 cGy per fraction. Subsequent to the completion of radiotherapy, all patients underwent surgery 4-6 weeks later. On histological examination of the surgical specimens, 51% of the cases (40) showed a complete response to therapy with no viable tumor cells. 49% of cases (38) had residual tumors ranging from a small focus to lesions extending through more than half the thickness of the cervical wall. p53 (mutant), bcl-2, p21 and bax proteins were studied on the paraffin sections of the biopsies (pretreatment) of those patients who failed to respond to RT and compared to similar studies on biopsies of patients who had a complete response to RT. In addition, the minichromosome maintenance (MCM) 2 proliferative marker was also done on all cases. Expression of all proteins was done using immunohistochemsitry. In the radioresistant cases, 15% (six cases) showed positivity for bcl-2 and p21, respectively, and 34% (13 cases) showed mutant p53. None of the radiosensitive tumors were positive for the above proteins. 75% of the radiosensitive tumors (30 cases) were positive for the bax antibody, whereas 81% of the radioresistant tumors (31 cases) were negative for bax. The MCM2 proliferative marker was positive in > 80% of cells in 81.5% of radioresistant tumors (31 cases) as compared to < 40% of cells that were positive in 70% of radiosensitive tumors (28 cases). The P-value for the biological markers was calculated using the chi-squared test, and was highly significant (P < 0.01) for all the parameters tested. However, there was no statistical significance by univariate analysis when the dose of radiation was analyzed with respect to the markers and the histological response. There was also no correlation between the radiation response and timing of surgery. The above data strongly suggest that bax, along with proliferative markers, could play a role in determining which tumors are likely to respond to radiation therapy. The presence of bcl-2, p21 and p53 could also be related to radioresistance of the tumors.

Apoptosis Regulatory Proteins↗