Malignant Diffuse Mesothelioma in Women: A Study of 354 Cases

Our plain-English summary of Malignant Diffuse Mesothelioma in Women: A Study of 354 Cases, by E.N. Pavlisko, B. Liu, C. Green, et al (The American Journal of Surgical Pathology, 2020).

The study

• Authors: E.N. Pavlisko, B. Liu, C. Green, T.A. Sporn, V.L. Roggli
• Journal: The American Journal of Surgical Pathology
• Published: 2020;44(3):293-304
• Cited by: 30 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We reviewed 354 cases of malignant diffuse mesothelioma (MM) in women from a database of 2858 histologically confirmed MM cases. There was a pleural predominance with 78% pleural MM and 22% peritoneal MM. The pleural tumors consisted of 72% epithelioid, 19% biphasic, and 9% sarcomatoid variant. The peritoneal tumors consisted of 82% epithelioid, 13% biphasic, and 5% sarcomatoid. The immunohistochemical profile was typical of what is well-accepted and previously described for MM. When examining tumor subtype and location, there was a trend toward epithelioid subtype and peritoneal location; however, this did not reach statistical significance. Age at the time of diagnosis ranged from 19 to 93 years with a mean of 60 years. The median age at time of diagnosis for pleural MM was 65 years and for peritoneal MM was 52 years. A further look at age and histologic subtype showed no statistically significant difference in age between MM subtypes. Survival was greatest for epithelioid variant, and this was magnified in the peritoneum. A majority of our cases were exposed to asbestos through a household contact. Asbestosis and parietal pleural plaque were present in 5% and 50% of cases with data, respectively. Fiber analysis data was available in 67 cases; 38 cases had elevated asbestos fiber burden, and tremolite was the most common asbestos fiber type detected. Commercial and noncommercial amphibole asbestos fibers were elevated in nearly equal numbers of cases.

In plain English

The authors reviewed 354 cases of malignant diffuse mesothelioma in women among 2858 confirmed cases in one author's consultation and medicolegal files, 1983 to 2010. Of these tumors, 275 (78%) were pleural and 79 (22%) peritoneal. Median age at diagnosis was 65 years for pleural and 52 for peritoneal tumors. Among 297 women in the survival analysis, median survival was 16.5 months (95% CI 13.3-19.0) for epithelioid (213), 9.0 months (95% CI 7.0-12.3) for biphasic (57) and 3.5 months (95% CI 2.0-5.0) for sarcomatoid tumors (27). Of 325 women with exposure information, 228 (70%) had household-contact exposure and 40 (12%) had occupational exposure. Asbestosis was found in 6 of 128 cases with data, parietal pleural plaques in 48 of 96. Lung fiber analysis in 67 cases found elevated asbestos levels in 38. Tremolite was the most common fiber; chrysotile was never the only fiber type. The authors concluded that peritoneal mesotheliomas in women, in general, are not likely to be caused by asbestos exposure. They noted that 95% of cases came from litigation and might not be representative.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective case series: review of cases from one pathologist's consultation and medicolegal referral files at a single institution
• Who was studied: 354 women with histologically confirmed malignant diffuse mesothelioma (pleural or peritoneal), out of 2858 cases in the database, 1983 to 2010 (Duke University, Durham, NC). Well-differentiated papillary and localized mesotheliomas were excluded.
• Exposure: Asbestos exposure history, grouped as household contact with an exposed worker, occupational/industrial, building occupant, environmental, or 'other'. Lung tissue fiber burden was measured by fiber type in 67 cases.
• Main results:
  • Of the 354 women, 275 (78%) had pleural and 79 (22%) had peritoneal mesothelioma.
  • Median age at diagnosis was 52 years (range 20 to 84) for peritoneal tumors and 65 years (range 19 to 93) for pleural tumors. The difference was statistically significant (P less than 0.0001).
  • Pleural tumors (275): 197 (72%) epithelioid, 51 (19%) biphasic, 25 (9%) sarcomatoid.
  • Peritoneal tumors (79): 65 (82%) epithelioid, 10 (13%) biphasic, 4 (5%) sarcomatoid.
  • Survival by histologic type included 297 women (213 epithelioid, 57 biphasic, 27 sarcomatoid), with 57 excluded. Median survival was:
• epithelioid: 16.5 months (95% CI 13.3-19.0)
• biphasic: 9.0 months (95% CI 7.0-12.3)
• sarcomatoid: 3.5 months (95% CI 2.0-5.0)
  Epithelioid survival was significantly longer than both other types (P less than 0.0001).
  • By tumor location, among 299 women included, median survival was 12.8 months (95% CI 10.5-14.5) for pleural and 15.0 months (95% CI 9.3-29.3) for peritoneal mesothelioma.
  • Among 52 women with peritoneal mesothelioma included, median survival was 28.3 months (95% CI 10.3-52.5) for epithelioid and 4.8 months (95% CI 1.0-13.3) for nonepithelioid tumors. For pleural tumors the figures were 16.0 and 8.0 months.
  • Among women with nonepithelioid tumors, survival in the household-contact-only group was described as marginally longer than in the occupational group (P = 0.018, adjusted P = 0.052). Among epithelioid tumors there was no significant difference by exposure category (P = 0.179).
  • Exposure information was available for 325 cases. Of these, 228 (70%) had household-contact exposure, and for 200 it was the only known source.
  • Among cases with exposure data, 40 (12%) had industrial/occupational exposure, 10 (3%) were building occupants and 3 (1%) had environmental exposure.
  • Among household-contact-only cases, the most common relationships were wives (95 of 194 with data) and daughters (53). Wives were diagnosed at an older average age (67 years) than daughters (48 years).
  • One or more objective markers of asbestos exposure (parietal pleural plaques, asbestosis or elevated fiber burden) were found in 57% of informative cases whose only known exposure was household contact.
  • Asbestosis was present in 6 of 128 informative cases (5%): 5 pleural and 1 peritoneal mesothelioma.
  • Parietal pleural plaques were present in 48 of 96 cases with data (50%). Of these 48, 45 (94%) had pleural tumors.
  • Of 67 cases with fiber analysis, 38 had elevated asbestos fiber burden, 5 were borderline and 24 were in the background range.
  • Across all 67 fiber-analysis cases:
• tremolite/actinolite/anthophyllite were the most common fiber types detected (82%), with tremolite predominating
• amosite and crocidolite were present in 48%
  • In the 38 cases with elevated asbestos fiber burden, the two groups of amphiboles were elevated in nearly equal proportions:
• noncommercial amphiboles (tremolite/actinolite/anthophyllite): 64%
• commercial amphiboles (amosite/crocidolite): 61%
  • Chrysotile was detected in 9% of fiber-analysis cases and was never the only fiber type.
• The authors' conclusion: The authors concluded that household contact was the most common exposure and a significant source of asbestos exposure. They found that tremolite was the most common asbestos type detected in women, while commercial and noncommercial amphiboles were elevated in nearly equal numbers of cases. They also concluded that some mesotheliomas in women cannot be attributed to asbestos, and that peritoneal mesotheliomas in women, in general, are not likely to be caused by asbestos.
• Limitations the authors state:
  • Fiber analysis was performed in fewer than 1 in 5 cases.
  • Most cases (95%) came from medicolegal litigation, so they may not be representative of all women with mesothelioma in the United States.
  • The finding of worse survival with occupational exposure among nonepithelioid tumors needs a larger sample to be validated.
  • Borderline fiber-burden cases are indeterminate as to whether they are elevated above background.
  • The lower percentage of asbestosis than in earlier reports is partly due to a 2010 redefinition of asbestosis.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Epithelioid, Biphasic Mesothelioma, Sarcomatoid, Statistical Significance, Histological Subtype, Peritoneum, Pleural Plaques.

Related studies

• Clinical picture, response to therapy, and survival of women with diffuse malignant peritoneal mesothelioma — G.H. Eltabbakh, M.S. Piver, et al. (1999)
• Diffuse malignant mesothelioma and synchronous lung cancer: A clinicopathological study of 18 cases — K.J. Butnor, N.A. Brownlee, et al. (2016)
• Chronic obstructive lung diseases and risk of non-small cell lung cancer in women — A.G. Schwartz, M.L. Cote, et al. (2009)
• Sarcomatoid Peritoneal Mesothelioma: Clinicopathologic Correlation of 13 Cases — E.N. Pavlisko, V.L. Roggli (2015)
• Breast cancer and occupational exposures in women in Finland — E. Weiderpass, E. Pukkala, et al. (1999)
• Surgical approach to pleural diffuse mesothelioma in Japan — K. Takagi, R. Tsuchiya, et al. (2001)

Browse more research in The American Journal of Surgical Pathology, or return to medical research.