Fatal Pulmonary Embolism and Cancer - a Post Mortem Study.

Introduction: During the period of 1965–1990 and 1991–2000, two separate analyses were carried out at King’s College Hospital, London, taking a retrospective review of all autopsy reports during this time. The initial aims of these reviews were to determine the number of deaths from autopsy-confirmed fatal pulmonary embolism (FPE) in hospitalised patients, and the clinical characteristics of these patients.

Methodology: Cases for inclusion were identified and data derived from manually examining copies of post-mortem reports. The data form recorded the patient gender, age, race, height, weight and surgical status. In addition, evidence of DVT, myocardial infarction (MI), stroke, chronic obstructive pulmonary disease (COPD), cardiac failure, infection or cancer was recorded from the autopsy report. Cases of fatal PE were classified as occurring in either surgical (if death occurred within 8 weeks of surgery), or non-surgical patients. The outcome of fatal pulmonary embolism was recorded as the cause of death only when the post-mortem stated that embolism was the main or contributing cause of death and identified emboli present either in the main pulmonary trunk or in the proximal right or left pulmonary arteries formed from the bifurcation of the main trunk. Emboli found in the distal pulmonary arteries after further division of the right and left pulmonary arteries were not included. Emboli derived from bone marrow, fat, tumour, or amniotic fluid were also excluded from the analysis. Ethical approval for the study was obtained from the local research ethics committee. The identity of deceased patients was protected by the use of code numbers on the data forms.

Results: Over the 35 year period there were 45,575 hospital deaths and 16,862 (37%) post-mortems. FPE was recorded as cause of death in 1,040 (6.2%) adult patients. Of these 85% (n=885) were in non-surgical patients, and 15% (n=155) in post-operative patients. Of the fatal pulmonary emboli, 347 of 1040 (33%) had either cancer (active malignancy) or a past history of cancer. Of this cancer group, 93% (n= 323) had an active malignancy, with 7% (n= 24) giving a past history of cancer. Cancer sites were gastro-intestinal in 34% (n= 119), lung 24% (n= 82), urological 10% (n= 33), gynaecological 8% (n= 29) and breast 8% (n= 28), 5% haematological (n= 17) endocrine 5% (n= 16), and dermatological 1% (n= 3). The majority of active cancers were found within the peritoneal cavity (60%, n= 194). Infection was the additional risk factor that was most prevalent in all those with FPE occurring in 32% (n=334), 76.3% (n=808) had one or more additional risk factors.

Conclusions: Most fatal pulmonary emboli occur in non-surgical patients, cancer is a very common association (33%). Active cancer is seen in 93% of all FPE deaths associated with cancer. Intra-peritoneal cavity tumours are the commonest type to be associated with FPE. Infection is a common associated risk factor.