Biomedical subjects

B O'Sullivan

Publications and source records attributed to B O'Sullivan.

At least 55 records · Page 3Linked to original sources

PubMed1999

The local management of soft tissue sarcoma.

Soft tissue sarcomas (STS) are rare tumors arising from the connective tissues. STS can arise at any anatomic site, can demonstrate varied behavior and prognosis, and therefore present a formidable challenge in management. The local treatment of STS demands technical complexity in the application of diagnostic tools, including pathology and imaging, as well as treatment approaches, including surgical ablation and reconstruction, radiotherapy, and, in defined cases, chemotherapy. The understanding of the management of these lesions is profoundly dependent on the multidisciplinary setting, where experience has been gained and skills are available to increase the likelihood of a successful result. Several proven options are available for optimal local management, and the choice of approach depends on the prevailing practice and resource profile of the treating center. With modern approaches, the local control rate can be expected to be at least 90% for extremity lesions, which constitute the most common STS. The experience in other anatomic sites is less favorable as a result of a combination of late diagnosis, technically difficult access sites, and possibly less familiarity with these less common presentations. The disappointing results make it all the more important for patients to be referred to a multidisciplinary setting with experience in sarcoma management to maximize the chance of successful local outcome.

Amputation, Surgical↗

PubMed1999

Approaches to local salvage of soft tissue sarcoma after primary site failure.

Improvements in pretreatment evaluation and the wider application of specialized multidisciplinary care have substantially reduced the risk of local recurrence for patients with soft tissue sarcomas arising at any site, and the recurrences that are still seen are often those that are most difficult to manage effectively. The management strategy for an isolated local recurrence of soft tissue sarcoma is usually similar to that used for primary disease. With appropriate pretreatment evaluation and salvage therapy that includes a multidisciplinary approach, most patients with local recurrence can expect local disease control and a good functional outcome. The development of effective management of a local recurrence is often a complex problem. The necessary decisions are influenced by the tumor location, disease extent, and previous local therapy. The need for specialized care is stressed. Patient evaluation, management strategies, and expected outcome for various clinical scenarios are discussed.

Amputation, Surgical↗

PubMed1999

Introduction

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Journal Article↗

PubMed1999

A matched control study of treatment outcome in young patients with squamous cell carcinoma of the head and neck.

OBJECTIVES/HYPOTHESIS: To determine if there is a difference in overall survival, cause-specific survival, and relapse-free rate between young patients (<40 years of age) with head and neck squamous cell carcinoma (HNSCC) and older patients (>40 years of age). STUDY DESIGN: A matched control study describing the outcome of 185 previously untreated HNSCC patients less than 40 years of age treated at the Princess Margaret Hospital, Toronto, Ontario, Canada, between 1958 and 1992. The young patient group was compared with a control group of older patients (> 40 years of age) which was selected randomly from an entire cohort of patients (n = 10,072) and matched for site, sex, and date of presentation. METHODS: The medical records were reviewed and data abstracted for demographic information, tobacco and alcohol use, family history, primary site, clinical stage, primary treatment, histology, the occurrence of residual or recurrent disease, salvage treatment, development of subsequent primaries, survival, and the eventual cause of death. The patient's TNM stage was reclassified according to American Joint Cancer Committee/Union Internationale Contre le Cancer (AJCC/UICC) 1992 criteria on the basis of the initial clinical description and staging investigations. A multivariate regression analysis was performed. To assess the importance of age as a prognostic factor for survival, the Cox proportion hazard model was used. Smoking status was also tested in the stratified Cox proportional hazard model. RESULTS: Tumor stage and treatment modalities were comparable in both groups. The 5-year, cause-specific survival in both groups was not statistically different (72% vs. 68%, P = .91). The young patient group had a significantly better 5-year overall survival compared with the older patient group (68% vs. 49%, P = .0011). Older patients developed more subsequent primary neoplasms than the younger patient population (18% vs. 8%, P = .005). There were significantly more females, an increased incidence of oral or oropharyngeal cancer, and fewer smokers in the young patient group. Smoking, however, had an important impact on outcome with all but one patient who developed a second primary in the upper aerodigestive tract having smoked. Multivariate analysis showed that only disease stage and cancer site were significant prognostic factors for survival. CONCLUSIONS: Young patients with HNSCC do not have a worse prognosis than a matched older patient group in this case-controlled study (power > 0.75 for a minimal detectable difference of 10% disease-free survival between the two groups).

Adult↗

PubMed1998

Ethmoid sinus cancer: twenty-nine cases managed with primary radiation therapy.

PURPOSE: To describe the outcome of patients with carcinoma of the ethmoid sinus managed with a policy of primary radiation therapy with surgery for salvage of persistent or progressive disease. METHODS AND MATERIALS: A retrospective chart review was undertaken of 29 patients with the diagnosis of carcinoma of the ethmoid complex who underwent treatment in the period between January 1976 and December 1994 at the Princess Margaret Hospital. Analysis was confined to those patients with epithelial invasive histology (squamous carcinoma, adenocarcinoma, or undifferentiated carcinoma) managed with curative intent with primary radiation therapy. The median patient age was 62, with a median follow-up time of 4 years. Staging was assigned according to a modification of the UICC 1997 system with 19 (66%) of patients presenting with T4 category tumors. The most common radiation dose regimes were 60 Gy in 30 daily fractions over 6 weeks, or 50 Gy in 20 daily fractions over 4 weeks. Outcome was analyzed with respect to overall survival, cause-specific survival, and local progression-free survival. The influence of a variety of clinical and therapeutic factors on outcome is discussed, the patterns of disease failure are described, and the rationale for this treatment approach is outlined. RESULTS: The 5-year rates of overall survival, cause-specific survival, and local progression-free survival were 39%, 58%, and 41%, respectively. A total of 18 of 29 patients died during the period of review. Of these, 12 deaths were due to ethmoid cancer, one was due to a second primary lung cancer, and five were attributed to nononcologic causes. No patients died due to treatment-related toxicity. Increasing T category predicted for worse outcome on univariate analysis. Local progression was the major cause of treatment failure and was documented in 15 of 29 patients treated (52%). Six patients were offered salvage surgery for local progression, of whom two remained disease free at 15 and 17 months follow-up. CONCLUSIONS: Outcome of patients with ethmoid cancer managed with primary radiation therapy with surgery for salvage is comparable to that achieved with planned combined modality approaches. Nevertheless, outcome remains poor and is dependent on the local extent of tumor, with 40-50% of patients eventually succumbing to disease.

Adenocarcinoma↗

PubMed1998

T1/T2 glottic cancer managed by external beam radiotherapy: the influence of pretreatment hemoglobin on local control.

PURPOSE: Pretreatment hemoglobin (Hb) level has been reported to be an important prognostic factor for local control and survival in various malignancies. However, in many settings, the adverse effect of a low Hb may be related to more advanced disease. The purpose of this analysis was to assess the influence of pretreatment Hb on local control in a large series of patients with a localized cancer (T1/T2 glottic cancer, AJCC 1992) treated in a standard fashion. MATERIALS AND METHODS: Between January 1981 and December 1989, 735 patients (median age 63; 657 males, 78 females) with T1/T2 glottic cancer were treated with radiation therapy (RT). The standard RT prescription was 50 Gy in 20 fractions over 4 weeks (97% of patients). Factors studied for prognostic importance for local failure included pretreatment Hb, age, sex, T category, anterior commissure involvement, subglottic extension, and tumor bulk (presence of visible tumor vs. subclinical disease). RESULTS: With a median follow-up of 6.8 years (range 0.2-14.3), 131 patients have locally relapsed for an actuarial 5-year relapse-free rate of 81.7%. The 5-year actuarial survival was 75.8%. The mean pretreatment hemoglobin level was 14.8 g/dl and was similar in all prognostic categories. On multivariate analysis, using the Cox proportional hazards model, pretreatment Hb predicted for local failure after RT. The hazard ratio (HR) for relapse was calculated for various Hb levels. For example, the HR for a Hb of 12 g/dl vs. a Hb of 15 g/dl was 1.8 (95% confidence interval 1.2-2.5). Previously established factors, including gender, T category, subglottic extension, as well as tumor bulk, were also prognostically important for local control. CONCLUSIONS: This analysis, in a large number of similarly treated patients, indicates that pretreatment Hb is an independent prognostic factor for local control in patients with T1/T2 carcinoma of the glottis treated with RT. The underlying biology of this observation needs to be explored, and using this information, it may be possible to develop strategies to improve treatment outcome.

Carcinoma, Squamous Cell↗

PubMed1998

Shape and roughness activate different somatosensory areas in the human brain.

Somatosensory stimuli are known to activate the postcentral gyrus, and neurons there fire when the skin is in contact with objects. Also neurons in the lateral fissure, the parietal operculum, fire when rough surfaces are felt. However the localization of somatosensory association areas in humans is largely unknown and differences in functional contributions between somatosensory association areas has not been previously demonstrated. For these reasons the regional cerebral blood flow was measured with 15O-butanol and positron-emission tomography in two groups of young volunteers discriminating the lengths, shapes, and roughness of objects with their right hand. Roughness discrimination activated the lateral parietal opercular cortex significantly more than did length or shape discrimination. A Boolean intersection of the cluster images showing the statistical significant increases of length and shape discrimination demonstrated that shape and length discrimination activated the same cortical field lining the anterior part of the intraparietal sulcus (IPA). Shape and length discrimination activated IPA significantly more than did roughness discriminaton. These findings demonstrate a separation in functional contributions of lateral parietal opercular cortex and IPA. The results indicate different cortical processing streams for the somatosensory submodalities microgeometry and macrogeometry.

Adult↗

PubMed1998

Similar decreases in local tumor control are calculated for treatment protraction and for interruptions in the radiotherapy of carcinoma of the larynx in four centers.

PURPOSE: Data on patients with cancer of the larynx are analyzed using statistical models to estimate the effect of gaps in the treatment time on the local control of the tumor. METHODS AND MATERIALS: Patients from four centers, Edinburgh, Glasgow, Manchester, and Toronto, with carcinoma of the larynx and treated by radiotherapy were followed up and the disease-free period recorded. In all centers the end point was control of the primary tumor after irradiation alone. The local control rates at > or = 2 years, Pc, were analyzed by log linear models, and Cox proportional hazard models were used to model the disease-free period. RESULTS: T stage, nodal involvement, and site of the tumor were important determinants of the disease-free interval, as was the radiation schedule used. Elongation of the treatment time by 1 day, or a gap of 1 day, was associated with a decrease in Pc of 0.68% per day for Pc = 0.80, with a 95% confidence interval of (0.28, 1.08)%. An increase of 5 days was associated with a 3.5% reduction in Pc from 0.80 to 0.77. At Pc = 0.60 an increase of 5 days was associated with an 7.9% decrease in Pc. The time factor in the Linear Quadratic model, gamma/alpha, was estimated as 0.89 Gy/day, 95% confidence interval (0.35, 1.43) Gy/day. CONCLUSIONS: Any gaps (public holidays are the majority) in the treatment schedule have the same deleterious effect on the disease free period as an increase in the prescribed treatment time. For a schedule, where dose and fraction number are specified, any gap in treatment is potentially damaging.

Carcinoma↗

PubMed1998

Re-irradiation for locally recurrent nasopharyngeal carcinoma.

Since 1989, 17 patients have undergone re-irradiation for locally recurrent nasopharyngeal cancer (NPC). The dose currently administered externally is 39.6 Gy in 36 fractions (BID) followed by an intracavitary boost (15-20 Gy). Disease persisted in five out of five patients treated palliatively. Eleven of 12 patients treated with curative intent achieved local control.

Adult↗

PubMed1998

Surgical salvage after failed radiation for paranasal sinus malignancy.

OBJECTIVE: To comment on the role of surgical salvage following failed initial treatment for paranasal sinus malignancy. DESIGN: A retrospective analysis of one hundred eighty patients treated at The Princess Margaret Hospital, Toronto, from 1976 to 1993. MATERIALS AND METHODS: Thirty-four of 95 patients (36%) who failed initial treatment underwent surgical salvage. Initial therapy in this group was radiation only (n = 27) and combined therapy (n = 7). Patient, tumor, and surgical data were recorded. There were 23 T4, three T3, six T2, and two T1 carcinomas. Survival, recurrence rates, and the influence of a variety of variables on outcome were analyzed. RESULTS: Two- and 5-year overall actuarial survival calculated from the date of diagnosis was 54% and 35%, respectively. Two- and 5-year overall actuarial survival calculated from the date of salvage surgery was 44% and 22%, respectively. Advanced age (P < .004), patients with T4 category disease (P < .04), and squamous cell carcinomas (P < .049) correlated with poorer outcome on univariate analysis. Local failure was the most common cause of death (n = 13; 65%). CONCLUSION: Salvage surgery has a limited role in the management of persistent or progressive disease following failure of initial treatment. Careful postradiation surveillance with endoscopic biopsy under general anesthesia and immediate surgical resection when appropriate may improve the salvage rate.

Actuarial Analysis↗

PubMed1998

Neurogenic sarcomas: experience at the University of Toronto.

OBJECTIVE: Elucidation of the natural history and optimal management of neurogenic sarcomas is not straightforward, because of diagnostic difficulties and the low incidence of this disease. The majority of neurogenic sarcomas are categorized and treated as soft tissue sarcomas, and only a few centers have sufficient experience to add to our understanding of these malignant tumors. This article proposes an algorithm for the management of these tumors. METHODS: A cohort of 18 cases of neurogenic sarcoma (overall mean follow-up period after oncological diagnosis, 33.7 mo), representing approximately 3% of all soft tissue sarcomas treated at the University of Toronto Musculoskeletal Oncology Unit (Toronto, Canada) between 1989 and 1995, were reviewed. The clinical and pathological criteria used to establish the diagnosis of neurogenic sarcoma, the presenting symptoms, the tumor size and grade, the ability to obtain tumor-free margins during en bloc resection, the time to recurrence, and the overall survival rates were noted. A centralized pathological review of the biopsy was undertaken in all cases. RESULTS: A metastatic survey demonstrated localized disease for 16 of the 18 patients. The overall management strategy for these 16 neurogenic sarcomas with localized disease was to obtain local control by en bloc resection. Tumor size, tumor grade, and, most importantly, the ability to obtain tumor-free margins were all relevant prognostic factors for survival. Tumor-free surgical margins were obtained for 11 of 16 patients, with 9 of these 11 patients remaining disease-free. In contrast, all patients for whom tumor-free margins could not ultimately be achieved died as a result of their disease. CONCLUSION: Based on our experience, we propose an algorithm for the management of these rare tumors, for both optimal patient care and oncological research.

Adolescent↗

PubMed1998

Function after subtotal scapulectomy for neoplasm of bone and soft tissue.

We describe the functional results in 14 patients (7 men, 7 women) after subtotal scapulectomy for primary bone and soft-tissue tumours at a specialist musculoskeletal oncology unit. Eight had chondrosarcomas, two Ewing's sarcomas, one aggressive fibromatosis and three soft-tissue sarcomas. The mean follow-up was 52 months (6 to 120). Analysis of residual symptoms and of range and strength of movement by physicians used the Musculoskeletal Tumour Society rating scale (MSTS). Physical disability was measured by the patients using the Toronto Extremity Salvage Score (TESS). All 14 patients are still alive, two with systemic disease. Nine had more than 80% of their scapula resected but the glenohumeral joint was preserved in all cases. Eight had full movement and another two achieved 90 degrees of flexion. The mean functional results were good to excellent in all except three patients (mean MSTS = 71.6 and TESS = 79.9). Two of these three patients had considerable pain as a result of brachial neuropathy. Scapulectomy gives an excellent functional result if the glenohumeral joint is preserved. The rotator cuff could be removed without a severe functional deficit provided that the deltoid was reattached to the scapular remnant and the trapezius.

Adolescent↗

PubMed1998

Cancer staging.

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Academies and Institutes↗

PubMed1998

The role of cancer staging in evidence-based medicine.

The classification of disease is a fundamental aspect of scientific medicine. Only when a specific condition has been recognized and characterized, can we start to acquire knowledge about it. Anatomic staging is a key element in the classification of malignant disease. The effectiveness of cancer treatment is almost always studied in groups of cases defined by stage. Clinical trials, therefore, create knowledge which is largely specific to particular stages of particular cancers. That knowledge can only be used to guide the practice of oncology if patients are staged. Staging the individual case permits the knowledge derived from previous experience to be used to guide the choice of treatment. The routine use of staging in a population also permits knowledge to be used to optimize the effectiveness of cancer control programs.

Evidence-Based Medicine↗

PubMed1998

Survey of Canadian doctors' attitudes to cancer staging.

OBJECTIVE: To collect opinions on the value of cancer staging, the impediments to realizing comprehensive staging and the support that may exist for providing stage information to cancer registries. DESIGN: The National Cancer Institute of Canada and the Canadian Committee on Cancer Staging have conducted an opinion survey. Opinions were sought about who should be responsible for allocating the stage, what criteria should be used to alter staging classification and whether population-based registries should contain comprehensive staging data. SETTING: The survey involved 1748 practising cancer specialists representing a cross section of Canadian physicians involved in the treatment and assessment of cancer patients. RESULTS: The overall response rate was 44.4%. Respondents gave broad support to the universal recording of cancer stage in Canada with 75.2% to 78.6% stating that staging is extremely useful for research, cancer statistics and caring for patients. Most respondents (98%) considered that all new cancer patients should have a specific stage assigned at the time of their first definitive treatment, and 78% believed that the clinician responsible for treating patients should determine the stage of cancer. A high proportion (73% to 81%) of respondents considered staging to be extremely important to define disease extent, make treatment decisions, estimate prognosis, facilitate consistent management and to compare results of treatment. The respondents consider lack of adequate information from pathology and imaging reports as barriers to staging. Only a small proportion of respondents were familiar with the organizations responsible for promoting and developing staging classifications. CONCLUSIONS: The Canadian survey showed strong support for universal staging and for the development of a central coordinated effort to promote cancer staging in Canada.

Academies and Institutes↗

PubMed1998

The consultation to develop a national strategy for cancer staging in Canada.

The lack of uniform recording of stage is a continued barrier to the success of cancer control activities. To review the role of staging, in 1997 the Canadian Committee on Cancer Staging (CCCS) of the National Cancer Institute of Canada (NCIC) formalised a national Consultation initiative with the input of Canadian oncology leaders and international experts on staging. A document was created from prior background work by the Committee and pre-circulated for comment. The document described the importance of cancer staging to patient care, epidemiological and clinical research, and cancer control programs. The document was refined through an iterative process over much of a year which included a formal workshop of the participants and other meetings. The Consultation reaffirmed, with evidence, the central role of staging in all aspects of cancer management. The report of the Consultation, endorsed by the Board of Directors of NCIC, included the following recommendations: 1) the recording of TNM stage by the treating physician should be a standard of care for every cancer patient in Canada where TNM applies, 2) the Canadian Council on Health Services Accreditation should include the TNM stage for every cancer patient as a requirement for hospital accreditation. In conclusion, this process represents an effective method for raising awareness about important medical issues such as staging which are fundamental to the management and control of cancer.

Academies and Institutes↗

PubMed1997

A comparison of different staging systems predictability of patient outcome. Thyroid carcinoma as an example.

BACKGROUND: There is no consensus regarding the comparison of staging classifications. Recently, numerous staging classifications for thyroid carcinoma have been described. This study was performed to evaluate the relative discriminating ability of these different staging systems. METHODS: A literature review was conducted to identify the available staging classifications used for thyroid carcinoma. To compare the various staging classifications, cause specific survival data from a retrospective review of 382 patients with papillary and follicular thyroid carcinoma treated at Princess Margaret Hospital were applied to the various staging classifications. The ability of these classifications to distinguish the stage groupings were compared in the following ways: 1) tabulating the numbers of patients within each stage group; 2) collapsing stage groupings into high and low risk groups and calculating mortality rates at 10 and 15 years; 3) summing observed deviations at 5, 10, and 15 years; and 4) calculating the proportion of variance explained (PVE) for each staging classification, using each classification separately as a prognostic factor in a Cox regression model. RESULTS: The application of the PVE model, the only method of the four that used statistical inference, showed no statistically significant superiority of any system over the TNM classification of the American Joint Committee on Cancer (AJCC) and the International Union Against Cancer (UICC) in their ability to discriminate stage groupings. CONCLUSIONS: Because the TNM classification of the AJCC and UICC is universally available and widely accepted for other disease sites, the authors recommend it for all reports of the treatment and outcome of patients with thyroid carcinoma. Individual research groups also may use an alternative, validated classification to report results, provided that the outcomes are also reported using the TNM classification to facilitate comparison between different centers.

Adenocarcinoma, Follicular↗

PubMed1997

The impact of residual disease on local recurrence in patients treated by initial unplanned resection for soft tissue sarcoma of the extremity.

BACKGROUND AND OBJECTIVES: "Unplanned excision" in soft tissue sarcoma (STS) is defined as the gross removal of tumor without preoperative staging or consideration of the need for removal of normal tissue around the tumor. This study evaluated whether unplanned excision in patients with extremity STS would have an impact on local relapse (LR), even if reexcision of the tumor bed was undertaken. METHOD: Two hundred thirty-nine (239) patients with primary, extremity STS treated with limb salvage surgery were included in this study. Of the 239, 78% were treated with surgery and irradiation. Forty-seven tumors were low-grade and 192 high grade. Mean tumor diameter was 7.5 cm. Twenty had local recurrences and 64 relapsed systemically. RESULTS: Only margin and prior surgery were significant in univariate analysis (P < 0.05, log-rank test). The Cox multivariate analysis revealed that both margin of resection (P < 0.001) and the status of the local tumor site (P < 0.05) at definitive surgery were significant predictors of local relapse. CONCLUSIONS: These results suggest that the presence of microscopic disease in the reexcised specimen following unplanned resection is a risk factor for local disease recurrence.

Adolescent↗