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Biomedical subjects

A P Kumar

Publications and source records attributed to A P Kumar.

At least 37 records · Page 2Linked to original sources
PubMed1990

Malignant melanoma in children: its management and prognosis.

Malignant melanoma is rare in children, representing 1% to 3% of all pediatric malignancies. Thirty-three children with malignant melanoma were treated at St Jude Children's Research Hospital from 1967 to 1988. Their ages ranged from 1 day to 20 years (median, 12 years); 23 were boys and 10 were girls; and 5 of the 33 (15%) were black. Four of the 33 children had been treated for a previous malignancy. In 3, melanoma arose within a bathing trunk nevus. The extremity was the most common site (13), followed by the trunk (9), head and neck (7), and perineum (1). In 3 patients the primary site could not be determined. Upon initial presentation to St Jude Hospital, 17 patients had localized disease (stage I), 10 had regional node involvement (stage II), and the remaining 6 patients had disseminated disease (stage III). Using both Clark's level and Breslow's thickness as indicators, the incidence, initial stage, prognosis, and survival were compared. By Clark's level, 7 patients, (6 of whom were stage I) were level II or III, and 22 patients were level IV or V. Though 16 of 22 level IV and V patients were initially stage I, 10 patients eventually developed progressive disease. Similar observations were noted when using Breslow's thickness to evaluate the primary. In 5 of 27 evaluable patients, Breslow's depth of invasion was less than 1.5 mm. All 5 of these patients were diagnosed with stage I disease and have not shown progressive disease.

Adolescent↗
PubMed1990

Wilms' tumor: reduced-dose radiotherapy in advanced-stage Wilms' tumor with favorable histology.

Fifty-two children with favorable histology Wilms' tumor who had residual abdominal disease (Surgical Stages III and IV) were treated from 1979 to 1988 on a protocol designed to assess the effectiveness of reduced radiation doses. All patients received three-agent chemotherapy, beginning within 1 week after surgery. To permit assessment of disease response to initial chemotherapy, radiation therapy was delayed for a median of 28 days after surgery (range, 14-71 days). Total doses of abdominal radiation were limited to 12 Gy, given as 150 cGy daily fractions; 18 patients with Stage IV disease received 12 Gy bilateral pulmonary irradiation. Two year disease-free survival was 85% and 71% for Stage III and IV, respectively (p = .24). Abdominal relapses occurred in 3 cases (5.7%). The interval between surgery and initiation of irradiation was not related to disease-free survival. Of several patient and disease-related factors analyzed, only patient age was related to outcome. Disease-free survival was 100% at 3 years for children under the age of 3 versus 78% for children greater than age 3 (p = .05). Reduced-dose abdominal radiotherapy in conjunction with multi-agent chemotherapy and surgery provided excellent disease control with minimal toxicity in advanced-stage, favorable histology Wilms' tumor.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Management and prognosis of head and neck sarcomas.

Between 1962 and 1988, a total of 104 patients with head and neck rhabdomyosarcoma (RMS) and 17 patients with nonrhabdomyosarcoma (NRMS) were evaluated and treated at St. Jude Children's Research Hospital. All parameningeal sites (middle ear, orbit, or nasopharynx) were excluded from further analysis; thus, 50 patients represent the cohort of head and neck sarcomas for this review. Survival was good in this group of patients, 28 of 50 being alive and disease-free at last follow-up. Twenty of the 38 patients with RMS were alive and disease-free. Similarly, 8 of the 12 patients with NRMS were disease-free at a median follow-up of 5 years. However, the site and size of the primary tumor impacted on the extent of the initial resection and further treatment in addition to surgery. Although the treatment policy evolved over time to a stage-specific strategy for treatment modalities, the data suggest that surgery alone may be sufficient initial therapy for a subset of patients. For patients in whom complete resection is not achieved, the addition of radiotherapy and chemotherapy may result in improved survival.

Adolescent↗
PubMed1989

Two decades of experience with testicular tumors in children at St Jude Children's Research Hospital.

From 1968 to 1988, 24 children and adolescents with malignant testicular tumors were treated at St Jude Children's Research Hospital. Pure yolk sac tumors (YST) were present in 13 cases; 11 patients had other types of nonseminomatous malignant germ cell tumors. Children with localized and totally resectable disease (stage I) were treated by orchiectomy alone; all others also received chemotherapy. Five of ten patients treated before the implementation of a multiagent chemotherapy protocol in 1979 have died. By contrast, all of the 14 patients treated on this protocol are alive. The improved survival during the past decade is attributable to better diagnostic imaging techniques, the availability of serum tumor markers to monitor disease activity, and more effective chemotherapy. Orchiectomy alone is sufficient treatment for patients with clinical stage I disease who show appropriate reductions in tumor marker levels after surgery. Modern platinum-based chemotherapy provides disease control in patients with higher stage disease.

Adolescent↗
PubMed1988

Chest wall resection for Ewing's sarcoma of the rib: an unnecessary procedure.

Approximately 10% of all cases of Ewing's sarcoma arise from a rib. Conventional management has included chest wall resection (3 or more ribs) and radiation therapy. These forms of therapy have led to complications such as scoliosis and local deformity. The addition of radiation therapy can result in damage to the lung and adjacent viscera and also potentiate pulmonary restrictive disease. Between 1971 and 1978, 9 patients were treated with surgery, radiation therapy, and combination chemotherapy (three- or four-drug regimen). Only 2 patients (22%) survive. Since 1979, 14 patients were entered into a new protocol consisting of sequential induction chemotherapy, followed by delayed surgical resection whenever feasible. Three patients had complete resection of their primary lesion at onset. Initially, 7 patients had either biopsy (N = 4) or incomplete chest wall resection N = 3). All 4 patients with biopsy only at diagnosis had excellent responses to induction chemotherapy, allowing delayed resection of the involved rib without chest wall resection. Overall, 12 of 14 patients (86%) treated since 1979 survive, with only 2 receiving radiation therapy for residual disease in the primary rib site.

Adolescent↗
PubMed1988

Teratoid Wilms' tumor: the St Jude experience.

The term "teratoid" Wilms' tumor has been used recently to describe an unusual type of tumor in which, although classic nephroblastoma tissue is present, there is a significant diversity of cell types and tissues present. Examination of tissue samples from 290 patients treated at St Jude Children's Research Hospital from 1964 to 1987 disclosed that three children had teratoid Wilms' tumor. All three children had renal tumors and two of them presented with bilateral pyeloureteral obstruction, uremia, and hypertension. When compared with classic nephroblastoma, two of the children with teratoid elements responded poorly to chemotherapy and irradiation, although no metastatic disease was identified. One child died with sepsis and renal failure; the other two are surviving disease-free for 7 1/2 years and 26+ months since diagnosis. Because of the tendency for bilateral involvement, ureteral obstruction, and uremia, and their relative resistance to chemotherapy and irradiation, surgery is the principal form of therapy for patients with these tumors.

Child, Preschool↗
PubMed1988

Reduced therapy for Wilms' tumor: analysis of treatment results from a single institution.

From 1968 to 1986, 192 patients from 0 to 17 years of age were enrolled in three consecutive protocol-controlled studies of Wilms' tumor at St Jude Children's Research Hospital. Tumors were completely excised at the time of diagnosis whenever possible, and patients were subsequently treated with chemotherapy and radiotherapy according to the initial extent of disease. All patients received dactinomycin and vincristine, with doxorubicin added to the regimens in studies 2 and 3. Chemotherapy was extended to 18 months in study 2 (n = 53), but was limited to 12 months for most patients in study 3 (n = 107). In the third study, radiation was eliminated altogether for patients with stage I or II tumors and was reduced to 12 Gy for those with more advanced disease. Intensification of chemotherapy in study 2 improved the 5-year relapse-free survival rate over that in study 1 (82% v 52%), but the accompanying increase in toxicity was considered unacceptable. Comparison of 2-year relapse-free survival rates in studies 2 and 3 indicated that the reduction of therapy in the latter trial did not jeopardize disease control: 88% v 86% for patients with stage II or III disease, favorable histology; 75% v 57% for the same stages, unfavorable histology; and 57% v 61% for stage IV patients. At least 80% of all patients enrolled in study 3 will be long-term survivors. We conclude that rescheduling of effective antitumor drugs and eliminating or reducing radiotherapy are feasible alternatives in the treatment of Wilms' tumor with favorable histologic features.

Adolescent↗
PubMed1987

Thoracotomy for pulmonary metastatic osteosarcoma. An analysis of prognostic indicators of survival.

Removal of pulmonary metastases of osteosarcoma by thoracotomy is an accepted treatment; however, few investigators have analyzed the value of various prognostic factors in estimating survival. A review of all patients undergoing thoracotomy for recurrent osteosarcoma with pulmonary metastases treated at St. Jude Children's Research Hospital is reported. Since 1968, two thirds (39/59) of all patients who developed pulmonary metastases have had a total of 66 thoracotomies. Nine patients are alive with no evidence of disease, and six additional patients are alive with disease. Analyzed in 39 evaluable patients, the prognostic factors that correlate with survival by univariate analysis are: sex, number of nodules detected radiographically and resected, completeness of resection, and tumor location (bilateral versus unilateral). By Cox regression analysis, only sex and the number of nodules detected either radiographically or during surgery, and resected, had statistically significant correlation with survival. Thoracotomy is curative for some patients with pulmonary metastatic osteosarcoma and Prognostic factors predictive for survival are defined.

Child↗
PubMed1981

Treatment of childhood rhabdomyosarcoma at St. Jude Children's Research Hospital, 1962--78.

Between March 1962 and December 1978, 153 children with rhabdomyosarcoma (RMS) received treatment at St. Jude Children's Research Hospital. As of January 1979, 62 of these patients were still alive. Between 1962 and 1968, 20 patients were not treated by protocol, and, between 1968 and 1979, another 13 have been registered as "nonprotocol"; 6 of these 33 patients survive. Since 1968, 120 patients received treatment by 3 stage-related, multiple-modality programs. In the first protocol, chemotherapy consisted of vincristine, cyclophosphamide, and dactinomycin; 14 of 34 patients have survived after 6 to more than 10 years. In the second treatment program, which used adriamycin in addition to the 3 drugs cited above, 20 of 56 subjects remain free of disease after more than 2 to 5.5 years; toxicity of the multiple agents given in combination with radiotherapy proved intolerable and led to a modified 4-agent protocol for patients admitted since early 1977. Of 30 in this latter group, 22 are alive. Forty of 44 patients who remained free of RMS for more than 2 years continue to survive.

Adolescent↗
PubMed1980

Retroperitoneal rhabdomyosarcoma in children. Results of multimodality therapy.

The clinical course of 18 consecutive children treated for primary retroperitoneal rhabdomyosarcoma was reviewed. At diagnosis, 8 patients had regional unresected tumor and 10 patients had disseminated tumor, including 3 patients with documented bone marrow infiltration by tumor. Following combined modality therapy, 14 of 18 patients achieved a greater than 50% tumor response (11 complete and 3 partial responses); 4 patients failed to respond and died of progressive disease within eight months of diagnosis. Among the 14 patients responding, 7 patients had subsequent reextension of active tumor three to 16 months (median, 9 months) following the onset of therapy. Three of the 7 remaining patients died of treatment complications, 2 of intestinal obstruction and 1 of disseminated histoplasmosis, within the first year of therapy and at post-mortem examination had no demonstrable tumor. Four patients are alive and free of active tumor for 10+, 10+, 32+ and 33+ months from diagnosis. Treatment complications have included hematopoietic depression, mucositis, enteritis, intestinal obstruction, excessive weight loss, malnutrition, and life-threatening infection. These results illustrate limitations in current combined modality therapy of retroperitoneal rhabdomyosarcoma and the necessity for future treatment modifications to both reduce morbidity and to improve survival.

Adolescent↗
PubMed1980

High-dose methotrexate used alone and in combination for measurable primary or metastatic osteosarcoma.

High-dose methotrexate with leucovorin rescue was used alone or in combination with Adriamycin and cyclophosphamide for the treatment of 27 osteosarcoma patients with measurable indicators of disease. Three patients developed complete responses of measurable lesions, two had partial responses, two had static disease, one had symptomatic improvement, and one had return to normal of physical findings following treatment of a flat bone primary osteosarcoma. While the doses and frequency of administration of high-dose methotrexate differed from those used by previous investigators, these results suggest that aggressive treatment with high-dose methotrexate must be attempted to further evaluate its efficacy as single-agent therapy for osteosarcoma patients not eligible for adjuvant chemotherapy trials.

Antineoplastic Agents↗
PubMed1978

Treatment strategy for nodular renal blastema and nephroblastomatosis associated with Wilms' tumor.

Nodular renal blastema and nephroblastomatosis were present in 8 of 118 patients (6.8%) with Wilms' tumor. Five of these 8 patients (63%) had bilateral Wilms' tumors. Two had hemihypertrophy. Preoperative renal angiograms were accurate in detecting these metanephric anomalies. The surgical approach consisted of removal of the most diseased kidney and biopsy for diffuse tumors and wedge resections for localized tumors for the remaining kidney. Postoperatively, radiation was administered when tumor extended outside the kidney. Chemotherapy consisted of vincristine and dactinomycin for 18 mo and adriamycin for 6 mo. This method of management resulted in tumor-free survival of these 8 patients for 1--44 mo (median 24 mo). Nodular renal blastema and nephroblastomatosis may possibly develop into Wilms' tumor. All of these three conditions respond to surgery, chemotherapy, and radiation. When a Wilms' tumor is encountered, it is better to explore and possibly biopsy the opposite kidney. There is a place for second-look laparotomy in this spectrum of congenital anomalies.

Child↗
PubMed1978

Ultrastructure of malignant histiocytoma arising in the acromion.

The ultrastructural features of a malignant histiocytoma of the acromial process of the scapula were studied. Material was obtained from two surgical biopsy specimens and an amputation specimen from the tumor. Cells possessing characteristics of histiocytes, fibroblasts, xanthoma cells, and multinucleated giant cells were present throughout the tumor. Smaller numbers of undifferentiated cells and lymphocytes were also observed. Intimate cytoplasmic interdigitations between adjacent tumor cells were found, and instances of degenerating intracytoplasmic cells, possibly representing phagocytosis, were observed. Specimens stained with periodic acid-Schiff reagent with and without exposure to diastase, examined by light microscopy, showed that numerous cells contained phagocytized material consisting of degenerating cells rather than cytoplasmic glycogen. Intraumor lymphocytes apparently represented an inflammatory reaction to the tumor. The tumor giant cells and xanthoma cells were probably modified histiocytes. Results of the study were compared with previous reports of ultrastructural studies of malignant histiocytoma of soft tissues. Fundamental similarities between such studies and this one suggested that the progenitor cell is a histiocyte, whether arising in bone or in soft tissues, and that the progenitor cell is capable of differentiation in both histiocytic and fibroblastic directions.

Acromion↗
PubMed1978

Combination chemotherapy for osteosarcoma.

Because of the great risk for development of pulmonary metastases following amputation for osteosarcoma, 24 consecutive patients with "clinically localized" osteosarcoma of an extremity were given adjuvant combination chemotherapy with adriamycin-cyclophosphamide-high-dose methotrexate-citrovorum factor. Thirteen of these patients remain free of tumor from 11 to 48 months following amputation. The median disease-free survival is estimated to be 18 months and the median survival 27 months. No relapses have been observed in any patients surviving free of disease beyond 23 months. Combination chemotherapy was also given to 16 patients whose disease was not localized; eight with pulmonary metastases at or following diagnosis, one with nodal metastases at diagnosis, two with osteosarcoma following radiation therapy for other malignant tumors, three with osteosarcoma of flat bones, one with parosteal osteosarcoma, and one with multifocal osteosarcoma. Three of this latter group of patients are surviving free of tumor at 8, 17, and 19 months from diagnosis. Two young patients died from complications of methotrexate and adriamycin toxicity.

Adolescent↗