Pulmonary Metastases In Colorectal Cancer: Review On Diagnosis,Management And Prognosis

Colorectal cancer is the third most common incidence of malignant tumor and fourth deadliest in the world.With better understanding of tumor biology and development of surgical technique,present available regional control of the disease is already quite promising.Yet,major concerns still remain for the control of the progressive disease,especially late stage cancer with distant organ metastases.Lung is the most common distant organ metastases after the liver from the primary colorectal cancer.It is the first organ reached by circulatory pathway beside the liver because of its vascular anatomy and circulatory flow.Other distant site of metastases such as brain and bone are proven most commonly accompanied with lung metastases in latest SEER database.Diagnosis of lung metastases are recommended to be confirmed with routine chest CT and tumor marker level detection,especially CEA.Other examination technique that can be run as supportive test such as MRI for other soft tissue and lymph node assessment,genetic and immunology testing may also be beneficial in confirmation and prognosis prediction of the disease.Careful pre-surgery assessment must be done with consensus discussion in a Multidisciplinary Team meeting,mainly to decide whether lung lesion can be defined as metastatic lesion and confirmed its resectability.Up til today,the most effective management for resectable metastatic lesion is surgical removal via thoracotomy or VATS.For local control of micronodule and other multiple oligometastatic nodule limited to the lung,image-assisted thermal ablation such as RFA,cryoablation and MWA or even laser-VATS.For locoregional and systemic control,combination of chemoregiments are still used as first choice.Genetic testing and molecular detection plays important role for systemic treatment selection,therefore it must be done especially in patient with non-resectable lesion and/or patient considered for adjuvant therapy.Prognosis factor of the overall survival in patient with colorectal lung metastases include;CEA level,multiple single-organ or multi-organ metastases,lymph node involvement,and overall systemic condition.Therefore,careful and integrated follow-up measure must be taken in order to prevent uncontrolled disease progression and death.