Surgical Treatment of Intraperitoneal Metastases From Lung Cancer

Two Case Reports and a Review of the Literature

Simone Sibio; Giuseppe Sigismondo Sica; Sara Di Carlo; Maurizio Cardi; Alessandra Di Giorgio; Bianca Maria Sollazzo; Paolo Sammartino

Disclosures

J Med Case Reports. 2019;13(262) 

In This Article

Discussion

Overall median survival in metastatic lung cancer is very poor. In recent studies it ranged between 3 and 12 months, depending on type of treatment.[8] Peritoneal metastases from extra-abdominal cancers are rare and have a poor prognosis. In a recent large population study by Flanagan et al., the overall incidence rate of peritoneal metastases from extra-abdominal cancers was 9%, mostly originating from breast cancer (40.8%), followed by lung cancer (25.6%), and melanoma (9.5%).[5] Satoh et al. reported a rate of 1.2% of peritoneal metastases complicating the clinical course of advanced lung cancer,[9] while in other autopsy series this rate was found to be 12%.[10] Therefore, it could be argued that a number of cases of peritoneal metastases remains undiagnosed or unreported in patients with lung cancer. A few studies reported isolated bowel metastases from non-small cell lung carcinoma (NSCLC) with very poor prognosis[4,9,10] and some others described the peritoneal diffusion of pleural mesothelioma.[11,12]

In gastrointestinal tumors, peritoneal metastases generally arise either from direct invasion of the bowel wall or from cancer cells spilled by surgical manipulation.[13] These mechanisms are not applicable to lung cancer. In stage IV lung cancer, pleural metastases at diagnosis are significantly associated with subsequent peritoneal spread, whereas no association between oncogene status and peritoneal disease has been reported.[6] Pleural serosa infiltration might eventually explain the peritoneal seeding, but this mechanism could not be considered in our cases since our patients had no pleural disease.

According to the two most recent systematic reviews, bowel obstruction is the most frequent clinical presentation although bleeding and perforation are also reported.[14,15] CT and positron emission tomography (PET) scans are useful tools for diagnosis in the late stages, while CT scan sensitivity is low at the early stage of peritoneal diffusion. In most patients, the time interval between primary lung cancer and peritoneal metastases ranges from 2 months to 4 years. The most frequent histology is NSCLC, with large cell cancer and adenocarcinoma being the most common subtypes. The prognosis for patients with peritoneal metastases from lung cancer is very poor regardless of the treatment, with a median survival rate of 2 to 4 months. In a recent review, Balla et al. found two cases of peritoneal metastases out of a sample of 91 patients with lung cancer with gastrointestinal metastases: the disparity with autopsy series suggests that most cases are asymptomatic or unreported.[16,17] Emergency surgery for bowel obstruction and extra-abdominal metastases, found in up to 60% of patients,[11,12] could be the main reasons for the poor prognosis. However, the patients reported in this study had an unexpected good outcome despite their emergency presentation and the presence of diffused peritoneal involvement in one of them. They reached, respectively, 3-year and 2-year disease-free survival and one of them is currently alive. The absence of extra-abdominal metastases might perhaps explain the unexpected long survival. However, our results suggest that a combined approach (surgery and chemotherapy) could be advocated in selected patients with peritoneal metastases from lung cancer with some survival advantages compared to standard treatment. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) in unconventional indications is occasionally reported in experienced tertiary centers,[2] most frequently from rare ovarian cancers, sarcoma, or neuroendocrine tumors, and, more rarely, from gastrointestinal stromal tumor (GIST), hepatocellular and cholangiocarcinoma and desmoplastic small round cell tumors. The gap existing between the small reported series data and the incidence rates in autopsy series could suggest that in most cases peritoneal metastases from lung cancer remain clinically silent.[16] Our results on these two patients might help in stimulating more awareness of this condition and in suggesting a strict follow-up: in fact, early diagnosis of peritoneal diffusion, which is probably often underrated, could allow a radical cytoreductive surgery providing some advantages to survival.

Considering the behavior of lung cancer, in particular, its tendency to early metastases because of its continuous dynamic state and large blood and lymphatic supply that spreads a large amount of neoplastic cells directly in the bloodstream,[18] the association of a strict follow-up and focused imaging techniques could help to identify selected cases to be treated, avoiding emergency "salvage" treatments that are difficult to perform even in dedicated centers.

High postoperative morbidity should be carefully considered when an extensive surgical treatment is planned on a patient with an advanced oncological stage. In our small series of two patients no major complications were observed, and maximal cytoreduction and HIPEC should not be discarded a priori as a treatment option. Further studies on this specific subset of patients could better clarify indications and limits.

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