Table 1. Characteristics of included studies and main objectives.
CEA: carcinoembryogenic antigen; HIPEC: hyperthermic intraperitoneal chemotherapy; ILC: invasive lobular carcinoma; IDC: invasive ductal carcinoma; MMP: matrix metalloproteinase; USA: United States of America
| Article | Design | Objectives | Total N | Methods | Mentioned limitations |
| Pattern of spread (N=10) | |||||
| Lamovec, 1991 (Slovenia) | Cohort study | Difference in metastatic sites between ILC and IDC | 226 | Retrospective review of autopsy records and histology | None |
| Antic, 2010 (USA) | Cohort study | Tumor type and single-cell pattern of peritoneal effusions in metastatic breast cancer | 819 | Retrospective review of patients’ pathologic reports and clinical files | None |
| Jain, 1993 (USA) | Cohort study | Differences in metastatic sites between ILC and IDC | 1391 | Retrospective review of clinical records | None |
| Inoue, 2017 (Japan) | Cohort study | Clinical significance of peritoneal metastases from breast cancer | 330 | Retrospective review of clinical records | None |
| Winston, 2000 (USA) | Cohort study | Pattern of spread of metastatic ILC to the chest, abdomen and pelvis | 57 | Retrospective review of CT images | No direct comparison with IDC; CT is not the gold standard for diagnosis; Biopsy-proven metastases not performed in all patients. |
| DiPiro, 2019 (USA) | Cohort study | Frequency, patterns and prognosis of ILC with abdominal metastases | 116 | Retrospective analysis of CT images | Retrospective design; Lack of generalizability (tertiary center); Variability in timing and number of images between patients; No cross-checking. |
| Kennecke, 2010 (Canada) | Experimental, correlational | Correlations between breast cancer molecular subtypes and distant metastatic site | 3726 | Tissue microarray and immunohistochemical analyses | Changes in adjuvant therapy guidelines over time; Overestimation of the risk of relapse; |
| Mitra, 2006 (USA) | Experimental | Role of intrinsic FAK (Focal Adhesion Kinase) activity in promoting tumor progression | 24 | Whole-body fluorescent microscopy in orthotopic breast cancer xenografts | None |
| Derksen, 2011 (Netherlands) | Experimental | Development of a preclinical model for breast carcinomatosis | 86 | Transgenic mice model and orthotopic breast cancer xenografts | None |
| Diagnosis (N=2) | |||||
| Noh, 2012 (Korea) | Experimental | Diagnostic precision of MMP-2 and MMP-9 in ascites and pleural effusions in metastatic breast cancer | 36 | Chemiluminescent enzyme immunoassay on body fluids for CEA detection; Zymography and ELISA for matrix metalloproteinase | Patients heterogeneity; Retrospective study; Small sample size; Arbitrarily defined cut-off levels. |
| De Mattos-Arruda, 2014 (USA) | Proof-of-concept study | Use of targeted massively parallel sequencing to determine the origin of abdominal metastases | 1 | Targeted capture massively parallel sequencing | Only one patient; Lack of generalizability due to BRCA1 mutation. |
| Prognosis and treatment (N=10) | |||||
| Bertozzi, 2015 (Italy) | Cohort study | Prognosis of breast cancer patients with peritoneal carcinomatosis compared to other metastatic sites | 289 | Retrospective patients’ charts review | None |
| Flanagan, 2018 (Ireland) | Cohort study | Prognosis of patients with peritoneal metastases from extra-abdominal primary tumors | 543 | Retrospective patients’ charts review | Missed cases due to under-reporting and due to the inclusion of hospitalized patients only. |
| Tuthill, 2009 (United Kingdom) | Cohort study | Management and prognosis of patients with peritoneal metastases from breast cancer | 44 | Retrospective patients’ charts review | Small sample size; Heterogeneity in treatment modalities. |
| Abu-Rustum, 1997 (USA) | Cohort study | Outcomes of surgical management in patients with breast cancer carcinomatosis | 40 | Retrospective patients’ charts review | None |
| Eitan, 2003 (USA) | Cohort study | Role of surgical resection in patients breast cancer metastases to the abdomen and pelvis | 59 | Retrospective patients’ charts review | None |
| Garg, 2005 (USA) | Cohort study | Etiology, predictive features of peritoneal carcinomatosis and prognosis of cytoreduction | 79 | Retrospective patients’ charts review | Selection bias; Incomplete clinical data due to the retrospective design; Evolution in treatment over time; Completeness of surgical resection is subjective. |
| Cardi, 2015 (Italy) | Cohort study | Cytoreduction and HIPEC in patients with peritoneal metastases from rare primary tumors | 27 | Retrospective patients’ charts review | None |
| Cardi, 2013 (Italy) | Case series | Outcomes of HIPEC in peritoneal metastases | 5 | Retrospective patients’ charts review | None |
| McLemore, 2005 (USA) | Cohort study | Treatment outcomes in patients with gastrointestinal and peritoneal metastases from breast cancer | 73 | Retrospective patients’ charts review | Article only includes women with pathology proven metastases. |
| Gusani, 2008 (USA) | Cohort study | Morbidity and mortality of HIPEC and cytoreduction in peritoneal carcinomatosis from different cancer types | 122 | Retrospective patients’ charts review | None |