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T Chua

Publications and source records attributed to T Chua.

29 records · Page 2Linked to original sources
PubMed1989

Breast cancer and pregnancy: the ultimate challenge.

An update on a series of 413 patients with carcinoma of the breast associated with pregnancy and referred to The Princess Margaret Hospital between 1931 and 1985 is presented. Coincident pregnancy is seriously detrimental to survival and, to a lesser degree, lactation. Subsequent pregnancies do not affect survival provided the pregnancy occurs at least one year after treatment for breast cancer, and preferably two years. Subsequent pregnancy may confer an improved prognosis. Interference in terms of a therapeutic abortion in breast cancer with coincident, lactational and subsequent pregnancies, is associated with decreased survival and ovarian ablation confers no benefit. Investigation and local treatment for coincident pregnancies should be limited to the absolute minimum necessary to achieve local control. Aggressive management should be reserved for acute life-threatening situations and then only after frank discussion with the patient. Adjuvant therapy is recommended after delivery and for lactational presentations, even if nodes are negative, due to the poor prognosis.

Adult↗
PubMed1988

The role of surgery in the management of thyroid lymphoma.

The role of surgery in the management of patients with primary lymphoma of the thyroid gland has been addressed after review of 61 patients treated at Princess Margaret Hospital between 1958 and August 1982, 46 of whom had clinical stage I and II disease confined to the thyroid gland or lymph nodes or both above the diaphragm. Postoperative radiation therapy was used in 34 patients, radiation therapy and chemotherapy in 11 patients, and chemotherapy alone in 1 patient. Analysis of disease progression, local relapse, and distant disease recurrence indicated that postoperative residual disease bulk predicted strongly for both local and distant disease progression. Overall cause-specific survival was 59% at 5 years, with a relapse-free rate of 46% at 5 years. Of those with less than 2.5 cm of residual disease after surgery, 80% achieved lifelong local disease control compared with 40% for those with residual disease in excess of 2.5 cm after surgery. Distant relapse rates were 7% and 23% for those with less than 2.5 cm and greater than 2.5 cm after surgery, respectively. The long-term survival rate for those with disease progression during this period was approximately 10%, with a median survival expectancy of 18 months. It is suggested that those patients without an antecedent cytologically based diagnosis of lymphoma undergo biopsy and removal of operable tumor without compromise of parathyroid glands, recurrent laryngeal nerves, or appearance. Those patients with an existing cytologic diagnosis of lymphoma and bulky and/or inoperable tumor may be more effectively managed with a combined chemotherapy-radiation therapy program.

Antineoplastic Agents↗
PubMed1987

Patterns of disease in localized extranodal lymphomas.

The site of origin of lymphoid tissue is an important determinant of lymphocyte migration patterns. The association of gastrointestinal (GI) and Waldeyer's ring lymphoma and the unique lymphocyte migration pattern of gut-associated lymphoid tissue (GALT) have been previously described. To establish whether predictive clinical patterns of disease occur in localized Non-Hodgkin's lymphoma, survival and relapse patterns for 496 patients with stage I and II non-Hodgkin's lymphoma (NHL) treated with loco-regional irradiation (XRT) alone were examined. We identified 139 patients with GALT lymphoma (defined as arising from primitive gut and including Waldeyers' ring, thyroid, and GI lymphomas) and 87 patients with extranodal non-gut-associated lymphoma (ENL). Survival and relapse data were assessed in multifactorial analysis to correct for previously identified other prognostic variables. GALT lymphomas (GALT-L) have a survival advantage compared with other ENL (P = .017) independent of stage and histology. A difference in distant relapse (DR) rate between GALT-L and other ENL (P = .0002) was also identified. The presentation site of localized extranodal NHL is predictive of clinical behavior and is an independent determinant of outcome. This may be an expression of lymphocytic origin and determinants of migration patterns.

Abdominal Neoplasms↗
PubMed1985

Role of radiation therapy in localized non-Hodgkin's lymphoma.

Relapse occurs in 50% of patients receiving radiation for clinical stage (C.S.) I and II nodal and extranodal non-Hodgkin's lymphoma (N.H.L.). Prior to the introduction of intensive chemotherapy those failing primary control with irradiation and most of those who relapsed died of their disease with a resultant overall mortality of 50%. An analysis of Princess Margaret Hospital results with radiation for C.S. I and II N.H.L. between January 1967 and December 1978 revealed that tumour bulk, age, stage and histology were of independent prognostic significance. It was possible to group patients using combinations of these attributes so that each group encompassed only patients with similar outcomes. Such prognostic groups were identified separately within the low grade and the intermediate plus high grade categories of the Working Formulation. Patients with a high probability of cure with radiation were so defined. Also those patients in whom chemotherapy would be optimal initial therapy were also defined. Such patients were in the intermediate plus high grade histology groups. Thirty percent of all patients with low grade histology lymphoma had an actuarial survival of 83%, and relapse-free rate of 63% at 10 years. By implication, approximately 20% of all patients with these histologies seen at the Princess Margaret Hospital for the same time period achieved prolonged relapse-free survival by localized therapy. This is at variance with the implications of staging from studies where laparotomy and multiple bone marrow biopsies have been used. Such aggressive staging procedures suggest truly localised disease in only 5-6% of patients with low grade lymphoma. A significant relationship between radiation dose and disease control was demonstrated only for patients with intermediate and high grade lymphoma of medium or large bulk. A minimum tumour dose of 30 Gy was required for optimal local control with radiation.

Adult↗
PubMed1985

Prognostic groups for management of localized Hodgkin's disease.

Two hundred fifty-two patients receiving radical irradiation for clinical stages I and II Hodgkin's disease between 1968 to 1977 had an actuarial ten-year survival rate of 78% and a relapse-free rate of 61%. Sixty-seven patients receiving chemotherapy followed by radiation had a 78% survival rate and a 63% relapse-free rate. Independent prognostic factors for survival and relapse were age, stage, and histology. Disease bulk was predictive only of relapse. Neither site of presentation above or below the diaphragm nor presence of mediastinal involvement was predictive for survival or relapse; however, patients with large mediastinal masses (greater than or equal to 10 cm absolute diameter) had a significantly higher intrathoracic failure rate with conventional mantle irradiation. Analysis of failure, according to age, clinical stage, and histologic type, showed three groups of patients defined according to the risk of relapse with radiation therapy: those with isolated upper cervical stage IA disease (group 1, relapse rate 8%), younger patients with localized stages I and II disease of favorable histologic type (group 2, relapse rate 35%), and older patients with extensive or symptomatic stages I and II disease of less favorable histologic type (group 3, relapse rate 70%). Subsequent analysis of radiation treatment volume indicates that the use of upper abdominal irradiation for patients in group No. 2 could yield results equivalent to those achieved with radiation therapy for surgically staged patients.

Adolescent↗
PubMed1984

Prognostic factors in nodular lymphomas: a multivariate analysis based on the Princess Margaret Hospital experience.

A total of 1,394 patients with non-Hodgkin's lymphoma were treated at the Princess Margaret Hospital between January 1, 1967 and December 31, 1978. Overall actuarial survival of 525 patients with nodular lymphomas was 40% at 12 years; survival of patients with localized (Stage I & III) nodular lymphomas treated with radical radiation therapy was 58%. Significant prognostic factors defined by multivariate analysis included patient's age, stage, histology, tumor bulk, and presence of B symptoms. By combining prognostic factors we have identified distinct prognostic groups within the overall population. Patients with Stage I & II disease, small or medium bulk, less than 70 years of age achieved 92% 12 year actuarial survival and a 73% relapse-free rate in 12 years of follow-up. These patients represent groups highly curable with irradiation.

Adolescent↗
PubMed1982

Results of treating Hodgkin's disease without a policy of laparotomy staging.

Results of the treatment of 780 primary patients with Hodgkin's disease at the Princess Margaret Hospital (PMH) between 1968 and 1977 are analyzed. Treatment decisions were based on the evaluation of the extent of disease by clinical methods. A marked improvement in relapse-free survival and overall survival was observed for 1973-1977 as compared to 1968-1972. This improvement did not result from differences in the distribution of important prognostic attributes (clinical stage, pathology, and age) between the two periods, and there was no improvement in our ability to rescue relapsed patients. Improved relapse-free and overall survival during the second period was observed for all stages in patients less than 50 years of age, but not in the older group. The improved survival of patients treated between 1973 and 1977 is attributed to more effective initial therapy, which reduced the fraction of patients who relapsed. These observations provide indirect evidence that relapse has a negative effect on prognosis, and that the initial treatment of patients with Hodgkin's disease should be designed to reduce the risk of relapse to a minimum without causing an unacceptable increase in late complications. The observed/expected incidence of acute leukemia and non-Hodgkin's lymphoma in the PMH series was increased to 41.9 and 13.9 respectively. The question of whether a policy of doing routine staging laparotomies improves the results of treatment of patients with Hodgkin's disease is considered only in general terms by comparing the total PMH series with the total Stanford Medical Center series of patients treated between 1968 and 1977. Relapse-free survival at 10 years is 48.9% and 66.8% respectively, at the two institutions, while overall survival at 10 years is identified.

Adult↗
PubMedDate not supplied

Accuracy of the automated assessment of left ventricular function with gated perfusion SPECT in the presence of perfusion defects and left ventricular dysfunction: correlation with equilibrium radionuclide ventriculography and echocardiography.

BACKGROUND: Gated single photon emission computed tomography (SPECT) with automated methods allows the quantitative assessment of left ventricular function and perfusion; however, its accuracy must be defined for patients with large earlier infarctions and severe rest perfusion defects, in whom the estimation of endocardial and epicardial borders might be more difficult, even with automated edge-detection techniques. METHODS AND RESULTS: We prospectively compared the automated measurements of left ventricular ejection fraction (LVEF) and volumes from rest-injected gated Technetium 99m (Tc99m) perfusion SPECT with equilibrium radionuclide angiocardiography (ERNA) in 62 patients and the assessment of regional function with echocardiography in 22 patients. Forty-six patients had an earlier myocardial infarction (mean defect size, 34% of left ventricle; SD, 12.7%; range, 8% to 56%); 27 patients had large defects (> or = 20% of left ventricle; LVEF range, 8% to 75%). LVEF, as determined with Cedars-Sinai software (quantitative gated SPECT), correlated well with ERNA (r = 0.941; y = 1.003x + 1.15; P<.0001; SE of the estimate = 6.3%; mean difference -1.3% for LVEF) in the entire study population and in the subgroups of patients with an earlier infarction, severe defects, and large infarctions (> or = 20% of the left ventricle). A correlation existed between gated SPECT and ERNA volumes (r = 0.882, y = 1.040x - 14.7, P<.0001 for end-diastolic volume; r = 0.954, y = 1.147x - 13.9, P<.0001 for end-systolic volumes with the count-ratio technique), but with wider limits of agreement. The exact segmental score agreement between gated SPECT and echocardiography for regional function was 79.8% (281 of 352, kappa = 0.682). CONCLUSIONS: Automated gated SPECT provides an accurate assessment of ejection fraction and regional function, even in the presence of an earlier myocardial infarction with large perfusion defects and significant left ventricular dysfunction.

Echocardiography↗