The work environment board: next stage in occupational health and safety.
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Canada↗
Biomedical subjects
R Sass
Publications and source records attributed to R Sass.
Pathologic findings from the National Surgical Adjuvant Breast Project (protocol 6). II. Relation of local breast recurrence to multicentricity.
One hundred ten local breast recurrences were observed in 1108 pathologically evaluable patients enrolled in NSABP protocol 6 who were treated by lumpectomy and followed for 5 to 95 months (average, 39 months). Eighty-six percent and 95% of all local breast recurrences were noted within 4 and 5 years, respectively, following lumpectomy. Life table analysis revealed their incidence to be 24% for those not and 6% for those receiving lumpectomy and breast irradiation. One hundred four (95%) of the breast recurrences involved the mammary parenchyma and the remaining 6 (5%) involved the skin and/or nipple only. Eleven (10%) of the former were noninvasive. The most common (86%) presentation of breast recurrence appeared to be a localized mass within or close to the quadrant of the index cancer. In 14% the recurrence not only involved the same quadrant, but was more diffuse within the breast extending to remote areas as well. This type was characterized pathologically by marked intralymphatic extension as well as involvement of the overlying skin and/or nipple after the fashion of so-called inflammatory or occult inflammatory breast cancer. The recurrences noted in the skin and/or nipple only were also pathologically characterized by intralymphatic involvement at these sites in the majority of instances. These two forms of breast recurrences appear to reflect the localized growth of highly aggressive invasive breast cancers. The concordance of histologic types and grades of the index and recurrent cancers implies that such events represent growth of overlooked tumor, a deficiency attendant with lumpectomy due to the extreme multifocal nature (not multicentricity) of some breast cancers and/or inadequacies in evaluating the lines of resection of lumpectomy specimens. Sources of error in regard to this latter are identified and guidelines for the examination of such specimens, as well as the assessment of margins, are presented. The observation that local breast recurrences noted following lumpectomy occurred within or close to the same quadrant as the index cancer, despite the presence of multicentric noninvasive cancers in 10% of the patients treated by total mastectomy, minimizes the biological and clinical significance of multicentric foci of cancer present in some breast cancers. Cancer measuring greater than or equal to 2.0 cm, having high histologic and nuclear grades, or intralymphatic extension, were found to have a statistically significant association with local breast recurrence in all patients following lumpectomy. A converse relationship was noted with tubular and scar cancers of types 1 and 4.(ABSTRACT TRUNCATED AT 400 WORDS)
Actuarial Analysis↗
Pathologic findings from the National Surgical Adjuvant Breast Project (protocol 6). I. Intraductal carcinoma (DCIS).
Seventy-eight examples of intraductal carcinoma (DCIS) were identified after pathologic review of 2072 specimens obtained from National Surgical Adjuvant Breast Project protocol 6. This randomized clinical trial compares the therapeutic merit of total mastectomy (TM) with lumpectomy (L), with (LX) and without (LO) postoperative irradiation. All patients were subjected to axillary lymph node dissection. Seven (14%) of the 51 patients with DCIS treated by L exhibited breast recurrence within or close to the site of the initial lesion 4 to 53 months (average, 16 months) after L. Only 2 (7%) of these events occurred in the 29 women treated by LX, as opposed to 23% in the LO group. No pathologic features were noticed that might have been considered predictive of local breast recurrence. The three DCIS recurrences and the four invasive forms noted are considered to represent overlooked or incompletely excised foci of cancer because of the multifocality (not multicentricity) of some breast cancers. The possibility that DCIS may represent a marker of risk for the development of cancer rather than a precursor lesion per se is suggested. Despite apparent difficulties in the pathologic diagnosis of DCIS as well as uncertainty concerning its natural history, no evidence was found to indicate that it represents a more ominous disease than invasive cancer. Indeed, treatment failure occurred in only one patient treated by LX and a similar number subjected to TM (4% versus 2%). Although these observations are short term (average follow-up, 39 months), estimates of the probability of local recurrence or survival suggest that they will not be significantly altered after longer periods of surveillance. Thus, there are no compelling reasons why DCIS may not be treated in a cosmetically acceptable manner by LX. A randomized clinical trial addressing this issue is now in progress.
Basement Membrane↗
Workplace health and safety: report from Canada.
This article represents a critical analysis of the major policy responses to workplace health and safety in Canada. It examines the deficiencies inherent in the legislative development of Joint Health and Safety Committees in most Canadian jurisdictions, the limitations regarding standard-setting of worker exposure to contaminants, and disincentive for employers to positively improve the workplace because of Workers Compensation legislation. Collective bargaining agreements in Canada have had only limited positive effects, while the ultimate legal sanction of criminal prosecution by the regulatory agencies has weakened enforcement and compliance of existing regulations. There has never been a successful criminal prosecution of an employer in Canada, even for multiple deaths. The article suggests the following four reasons for this "underdevelopment" of occupational health and safety in Canada: the concealment of the dimension of the incidence of industrial disease based on Workers Compensation Board statistics; the application of an incorrect theory of causation of both industrial disease and injury by both managers and government administrators of occupational health and safety programs; the resistance of both senior and middle managers against increased worker participation in both work organization and job design questions; and the general "moral underdevelopment," rather than ignorance, of managers in favoring economic considerations or values at the expense of worker health and safety. In light of the magnitude of the problem and the deficiencies of existing policy approaches, the author proposes the need for greater workplace democratization of production and industry as a necessary and sufficient reform of workplace health and safety.
Accident Prevention↗
Tissue mast cells in breast cancer.
The total number of mast cells and the number of such cells observed within and at the periphery of invasive breast cancers from 424 patients enrolled in protocol 4 of the National Surgical Adjuvant Breast Project were correlated with 38 other pathologic and 6 clinical features. High total mast cell counts as well as those within and at the periphery of the cancers were found to be significantly (p less than or equal to .05) associated with a patient age less than 50 years and the degree of tumor lymphoid cell reaction. The latter has also been found to be related to young age and other pathologic characteristics related to mast cell content. This suggests that the mast cells may simply represent another cell type of this reactive change. No differences in 10 year disease-free survival were detected in patients without mast cells and those exhibiting varying numbers of such cells. This information indicates that identifiable mast cells do not represent a prognostic pathologic discriminant in patients with breast cancer. However, this does not unequivocally exclude a role of mast cell secretory products, since only intact and not degranulated or disrupted forms of these cells can be counted.
Actuarial Analysis↗
Glycogen-rich, clear cell breast cancer: with comments concerning other clear cell variants.
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Breast Neoplasms↗
Biologic considerations regarding the one and two step procedures in the management of patients with invasive carcinoma of the breast.
Investigation of the biologic significance of delay between biopsy and mastectomy was performed upon women with invasive carcinoma of the breast in protocol four of the NSABP. Since the period of delay was two weeks or less in approximately 75 per cent, no comment concerning the possible effects of longer periods can be made. Life table analyses failed to reveal any difference in ten year survival rates between patients undergoing radical mastectomy management by the one and two step procedures. Similarly, no difference in adjusted ten year survival rate was observed between women managed by the two step procedure who did or did not have residual tumor identified in the mastectomy specimen after the first step or biopsy. Importantly, the clinical or pathologic stages, sizes of tumor or histologic grades were similar in women managed by the one and two step procedures minimizing selection bias. The material used also allowed for study of the possible causative role of biopsy of the breast on the development of sinus histiocytosis in regional axillary lymph nodes. No difference in degree or types of this nodal reaction could be discerned in the lymph nodes of the mastectomy specimens obtained from patients who had undergone the one and two step procedures. This finding indicates that nodal sinus histiocytosis is indeed related to the neoplastic process, albeit in an undefined manner, rather than the trauma of biopsy per se as has been suggested. These results do not invalidate the use of the one step procedure in the management of patients with carcinoma of the breast. Indeed, it is highly likely that it will be commonly used now that breast-conserving operations appear to represent a viable alternative modality for the primary surgical treatment of carcinoma of the breast. Yet, it is apparent that the one step procedure will be performed for technical and practical rather than biologic reasons.
Actuarial Analysis↗
Pathologic findings from the National Surgical Adjuvant Breast Project (Protocol No. 4). XI. Bilateral breast cancer.
Sixty-six confirmed instances of clinically metachronous second breast cancers were encountered over a 10-year period in 1578 women with invasive breast cancer enrolled in Protocol 4 of the National Surgical Adjuvant Breast Project (NSABP). Seven of the second cancers were in situ, yielding an incidence of 3.7% invasive and 0.5% noninvasive cancers. Except for a peak of 1.75% in the second postoperative year, the annual incidence based on patients at risk was constant and less than 1%. Ninety-three percent of the second cancers occurred within 7 years and 80% within 5 years following mastectomy for the initial primary. All of the second cancers were regarded as being primarily of mammary origin exhibiting either: (1) an in situ component; (2) dissimilar but well-recognized patterns of primary breast cancers; or (3) the appearance of scar cancer, a recently described morphologic feature characteristically observed in some primary breast cancers. A search for factors that might be predictive of bilaterality was performed. Thirty-eight pathologic and eight clinical factors were assessed, including family history. Although the latter was 1.5 to 2 times more frequent in patients with bilateral disease, this estimate was not statistically significant. On the other hand, a statistically significant association with bilateral disease was found when the initial tumor measured more than 2.0 cm, was associated with invasive cancer or proliferative fibrocystic disease, nipple involvement, absent nodal sinus histiocytosis, lobular carcinoma in situ in the vicinity of the dominant mass, or was of the lobular invasive or tubular types. However, the degree of risk of these discriminants was no greater than 2 to 3:1. Despite the clinical scrutiny imposed by the NSABP protocol second tumors measured only 1 cm less than the first, measuring on average 2.4 cm, which reflects the difficulty attendant on the clinical detection of so-called early breast cancers. Yet, no significant difference in pathologic nodal status was noted between the first and second cancers or that of patients with unilateral disease. Furthermore, there was no difference in survival rate between patients who developed a second cancer and those with unilateral disease.(ABSTRACT TRUNCATED AT 400 WORDS)
Adult↗
Pathologic findings from the National Surgical Adjuvant Project for Breast Cancers (protocol no. 4). X. Discriminants for tenth year treatment failure.
A search for prognostic discriminants of treatment failure in the tenth postmastectomy year was undertaken in 614 patients enrolled in protocol no. 4 of the National Surgical Adjuvant Project for Breast Cancers treated by radical mastectomy. Exploratory analyses of 38 pathologic and 6 clinical features disclosed 16 and 13 variables significantly related to nodal status and treatment failure, respectively. However, multivariate analyses with life tables adjusted or controlled for nodal status revealed that patients whose tumors measured less than 2 cm had a more favorable clinical course. All of the characteristics were also explored when patients were stratified according to numbers of nodal metastases, the most significant prognostic discriminant for disease-free survival in the tenth year. A germinal center predominance lymph node pattern and high histologic grade according to our conventional grading method were observed to adversely influence disease-free survival in patients with negative nodes. A strong trend in this manner was also observed with tumors greater than or equal to 2 cm and types 3 and 5 scar cancers. Histologic grade and tumor size were significantly recognized as discriminatory in patients with 4+ nodes but no factors were significantly observed in the group of patients with 1 to 3 positive nodes. A possible explanation for this inconsistency is discussed. For the most part, these factors were also encountered by us previously at the 5-year postoperative period. Only the presence of 13+ nodal metastases and types 3 and 5 scar cancers and cancers without scar appeared to discriminate success or failure between the fifth and tenth year. It is therefore concluded that nodal category, germinal center predominance, histologic grade, and tumor size, in the contexts noted, represent strong prognostic discriminants exerting a rather constant influence on disease-free survival at least to the tenth postmastectomy period. The prognostic value of categorizing those patients with 4+ positive nodes into subgroups with 4 to 6, 7 to 12 and 13+ is reaffirmed. The actual disease-free survival of patients in the tenth year was not strikingly different from that observed previously by us at 5 years in this cohort.
Breast↗
Scar cancers: pathologic findings from the National Surgical Adjuvant Breast Project (protocol no. 4) - IX.
The uncomplicated non-encapsulated sclerosing lesion (NESL) or radial scar of breast is a banal lesion which may be confused with tubular carcinoma. Yet, that the latter may arise in such scars is strongly suggested by the recognition of examples portraying morphologic features consistent with such 'early' transformation. Further, 38% of 1569 cases of unequivocal invasive breast cancers from patients enrolled in the National Surgical Adjuvant Breast Project, protocol 4, were found to be associated with scar. The scar in 14% of these was strikingly similar if not identical morphologically with the NESL or radial scar (type 1 scar cancer). Four other types of scar were identified. It is uncertain whether these represent variations of the NESL or are unique. However, each type possessed some distinguishing pathologic characteristics as disclosed by contingency table analyses of 36 histopathologic and 6 clinical features of these cancers. Most importantly, 6-year postmastectomy survival was significantly better as revealed by life-table analyses for patients whose cancers were designated as types 1 and 4 than for those with other scar types or in whom their cancer lacked scar. This relationship was found to be independent of nodal status. Ductal obliteration, a common finding in the banal NESL and scar cancers, has been previously suggested to play a role in their evolution. Our observations indicate that vascular obliterative alterations may be equally or perhaps even more significant in this regard. This as well as other features suggests an analogy between them and so-called scar cancers of the lung. Attention is directed to the prognostic significance of type and degree of tubule formation observed in some breast cancers. The results suggest a revision of the scheme utilized for the histologic grading of breast cancers. However, it appears valid to simply categorize breast cancer into well-differentiated (histologic grades 1 and 2) and poorly differentiated (histologic grade 3) types. Our data does not support the hypothesis that tubular cancer may 'progress' into less differentiated forms.
Adenocarcinoma↗
Accident proneness: science or non-science?
The "accident proneness" thesis has been with us since the early 1900s. The early statistical studies that reputedly provided the scientific basis for this notion are examined and found to be lacking due to methodological errors and a fragmented view of industrial life. Accident proneness, as originally envisioned, has no empirical foundations. It has, however, become part of the tactical armanentarium used in "blaming the victim" for industrial accidents. It focuses on the personal characteristics of workers in relation to accident causation, while de-emphasizing the role of dangerous work environments. In this respect, it has acted as a barrier in the development of preventive occupational health and safety principles and practices. The notion has endured not only because it is tactically advantageous, but also because many members of the professions that deal with workplace accidents have accepted it without reservation and lent it credence. For the purposes of industrial accident prevention, however, it would be more appropriate to discard this notion in favor of a more integrated and broader understanding of the nature of the interaction between workers and their socio-technical work environment.
Accident Proneness↗
The crystal sheaths from bivalve hinge ligaments.
The aragonite crystals in the molluscan bivalve hinge ligament are surrounded by an organic sheath which is distinct from the remainder of the ligament matrix. Methods have been developed to isolate these sheathed crystals from the ligaments of Spisula solidissima and Mercenaria mercenaria employing a papain digestion of the matrix protein. The sheathed crystals from Spisula have a CaCO3/protein ratio of 11.1 and those from Mercenaria a ratio of 29.6. The sheathed crystals and the empty crystal sheaths have been examined by electron microscopy for structural integrity. The sheath proteins exhibit much smaller proportions of the amino acids glycine and methionine than the hinge ligaments. These are characteristic amino acids of high concentrations in the hinge ligaments of both species. The concentrations of acidic and basic amino acids are increased about two fold in the sheaths over those of the ligaments. Otherwise there is little similarity in the amino acid composition of the sheaths in the two species. However, SDS electrophoresis shows the sheaths of both to contain a major protein component with a molecular weight of about 25,000. The sheath protein from the Mercenaria ligament contains about 5% carbohydrate and that of Spisula sheaths less than 1% carbohydrate.
Amino Acids↗
Enzymatic hydrolysis of poly-DL-lysine.
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Amylases↗
Occupational health.
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Occupational Medicine↗