Complete Resection Of Pulmonary Metastases Research Articles

Prognostic Significance of the Immunological Indices in Patients Who Underwent Complete Resection of Pulmonary Metastases of Colorectal Cancer.

The neutrophil-to-lymphocyte ratio (NLR) and the density of tumor-infiltrating lymphocytes (TILs) have been reported as immunological prognostic factors for various cancers. We evaluated the association between the prognosis and the immunological status in patients who underwent complete resection of pulmonary metastases of colorectal cancer (CRC). We evaluated the associations between the NLR before the resection of pulmonary metastases and the relapse-free survival (RFS) or overall survival (OS), or between the density of TILs in the pulmonary metastasis and the RFS or OS. The RFS and OS were significantly worse in the NLR-High group than in the NLR-Low group. The RFS was significantly longer in the CD3+TILs-High group than in the CD3+TILs-Low group. The NLR and the density of TILs may have prognostic significance in patients who undergo complete resection of pulmonary metastases of CRC.

Long-Term Outcomes of Pulmonary Metastasectomy for Uterine Malignancies: A Multi-institutional Study in the Current Era

BackgroundInformation on pulmonary metastasectomy (PM) for uterine malignancies in the current era is limited. In the present study, we analyzed the clinical course and results of PM for uterine malignancies in the era of modern imaging diagnostics to clarify the role of PM in the current era in a multi-institutional setting.MethodsFifty-seven patients who underwent PM for uterine malignancies between 2006 and 2015 were retrospectively reviewed. The short- and long-term outcomes, along with factors associated with the prognosis, were analyzed. Details of the clinical course after PM were described.ResultsThe mean age of patients was 59.4 years. The primary tumor was located in the uterus corpus in 34 cases (60%) and in the uterus cervix in 23 cases (40%). The median disease-free interval (DFI) was 32 months. Forty patients (70%) received fluorine-18-2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography before PM, and complete resection was achieved in 52 patients (91%). Postoperative complications occurred in 4 patients (7%). Of the 52 patients who underwent complete resection of pulmonary metastases, 28 experienced recurrence, and among these, 17 (60%) underwent local therapy, including six repeat PMs. Among the 52 patients who underwent complete resection, the 5-year relapse-free survival rate was 40.7% and the 5-year overall survival (OS) rate was 68.8%. The univariate analysis revealed that a DFI of ≤ 24 months was associated with significantly poorer OS.ConclusionsPM for uterine malignancies is safe and provides favorable long-term outcomes in selected patients. Patients with a DFI of > 24 months have better OS and are good candidates for PM.

P2.15-07 Bimanual Examination Is Indispensable in the Surgery of Lung Metastatic Tumors!

Thoracic computed tomography (Th CT) is used to evaluate the surgical outcome of lung metastatic tumors. However, Th CT is often inadequate on the detection of millimetric lesions and it alone is a problematic for guiding complete resection. It is recommended for complete resection that the intraoperative bimanual palpation of the lung to be used with care and meticulously. In addition, there are studies for minimally invasive surgical methods may be an alternative to thoracotomy where bimanual evaluation is not possible. In this study, we aimed to evaluate the number of radiological and pathological metastases in patients who underwent metastasectomy with muscle conservative thoracotomy (MCT). Between 2008 and 2018, 204 patients with metastatic lung tumors who underwent metastasectomy were included in the Department of Thoracic Surgery, Ankara University Faculty of Medicine. Preoperative Th CT imaging of all patients was evaluated in a multidisciplinary council. The relationship between the numbers of metastases detected by pathological examination of patients and the number of pulmonary nodules reported as 'metastasis' in preoperative Th CT was retrospectively analyzed. 55% (n: 111) of the patients were F, 45% (n: 93) were M, mean age was 46.4 (13-77). %25 (n:52) of two hundred and four patients had bilateral, 3% (n: 8) of the patients had 3 and 1% (n: 4) of the patients had 4 metastasectomy with MCT due to contralateral lung metastasis or re-metastasectomy. The number of pulmonary nodules detected in Th CT was 740 (mean: 2,6), although the number of pulmonary nodules resected was 1503 (mean: 5,29). In histopathological evaluation of these nodules, 1120 (mean: 3,94) were reported as metastases. 2,03 fold of the nodules detected in Th CT were detected by bimanual intraoperative examination and 1.5 fold of nodules detected in Th CT were pathologically assessed as metastasis. Primary tumor numbers and histologies of 1120 metastatic nodules respectively; 42% (n: 475) were epithelial tumors and 58% (n: 645) were mesenchymal tumors. In this study, 740 pulmonary nodules were reported in Th CT of 204 patients. However, 763 additional pulmonary nodules were detected by bimanual palpation. 49.8% (380/763) of 763 additional pulmonary nodules were metastatic. Although minimally invasive surgery is a successful method for the surgery of many thoracic malignancies, bimanuel palpation of the lung with open surgery is still an effective method for the complete resection of pulmonary metastases. Bimanual examination is indispensable especially in the pulmonary metastasectomy of sarcomas.

Significance of PD-L1 expression in pulmonary metastases from head and neck squamous cell carcinoma

BackgroundThe mechanism by which tumors escape the immune system has been actively investigated and is partly explained by the programmed death-1 (PD-1) and its ligand (PD-L1) pathway. This study is aimed at clarifying the prognostic significance of PD-L1 expression in patients with surgically resected pulmonary metastases of head and neck squamous cell carcinoma (HNSCC). Patients and methodsA retrospective review was conducted of 26 HNSCC patients who underwent complete resection of pulmonary metastases. PD-L1 expression in both the primary and metastatic tumors was evaluated using immunohistochemistry (anti-PD-L1 antibody, clone SP263). High PD-L1 expression was defined as ≥50% of tumor cells with positive staining. Survival and prognostic impacts following pulmonary metastasectomy were analyzed based on the PD-L1 expression level. ResultsThe patients included 23 men and 3 women, with a median age of 65 years. Six (23%) of the pulmonary metastatic cases showed high PD-L1 expression, while their corresponding primary lesions had low PD-L1 expression. The 5-year overall survival rate after pulmonary metastasectomy was 57.6% in all cases. The 5-year overall survival rates were 72.5% and 16.7% in the low and high PD-L1 groups, respectively (p < 0.001). Multivariate analysis demonstrated that high PD-L1 expression and older age (>65 years) correlated independently with a shorter overall survival (p < 0.001). ConclusionsHigh PD-L1 expression in pulmonary metastases could be an independent predictor of poor outcome in HNSCC patients undergoing pulmonary metastasectomy. This is the first report evaluating the prognostic implication of PD-L1 expression in metastatic HNSCC.

Surgical and non-surgical management of repeat pulmonary metastasis from sarcoma following first pulmonary metastasectomy.

Although repeat pulmonary metastasectomy for sarcoma is not uncommon and associated with a favorable survival in select patients, there is a paucity of data on the demographics and tumor characteristics of patients with repeat pulmonary metastasis following complete resection of pulmonary metastases from osteogenic or soft tissue sarcoma. A retrospective chart review was performed to identify patients with isolated repeat pulmonary metastasis after complete resection of pulmonary metastases from sarcoma at Kyoto University Hospital between January 1990 and December 2014. Isolated pulmonary metastasis was defined as limited to presumable pulmonary metastasis according to the follow-up radiologic workup. Thirty-five patients were identified to have repeat pulmonary metastasis. Thirty patients underwent attempted repeat pulmonary metastasectomy (including 21 undergoing documented complete resection and 7 undergoing documented incomplete or aborted resections). Five patients received non-surgical management. The median follow-up period was 16months (range 1-234) from repeat pulmonary metastasis. The five-year overall survival of the whole patient cohort and those undergoing repeat pulmonary metastasectomy were 37.6 and 41.1%, respectively, from repeat pulmonary metastasis. A majority of patients with repeat pulmonary metastasis from sarcoma undergo repeat metastasectomy, which is associated with favorable survival outcomes. However, a greater accumulation of data on non-surgically managed patients is needed as such information is currently limited available.

Long-Term Outcomes After Surgical Resection of Pulmonary Metastases From Colorectal Cancer

Surgical resection has been widely performed on patients with pulmonary metastases from colorectal cancer with favorable outcomes. However, there are currently no standard surgical indications for pulmonary metastases. We reviewed 94 patients who underwent complete resection of pulmonary metastases from colorectal cancer between November 1991 and April 2013. The cumulative survival rate after pulmonary metastasectomy was calculated, and prognostic factors for long-term survival were analyzed. There were 60 men and 34 women, and their median age was 66 years. The 5-year survival rate was 45.5% after pulmonary metastasectomy. The 5-year survival of patients with colon and rectal cancers was 62.4% and 33.8%, respectively (p = 0.030), and the 5-year survival of those with normal and high carcinoembryonic antigen (CEA) levels before pulmonary resection was 57.0% and 30.9%, respectively (p = 0.038). Multivariate analysis revealed the preoperative CEA level was an independent prognostic factor. Recurrence was identified in 65 of the 94 patients (69.1%) after pulmonary metastasectomy, and the patients who underwent surgical resection for recurrent lesions in the liver or lungs, or both, had better survival than those who received other treatments or palliative care. Surgical resection offers a chance to prolong survival in colorectal cancer patients with resectable pulmonary metastases. Owing to the high recurrence rate, careful postoperative follow-up for early detection is recommended, and even for recurrence, surgical resection should be considered for better survival if the lesions are limited to the liver or lungs, or both.

Prognostic factors in patients undergoing complete resection of pulmonary metastases of colorectal cancer: a multi-institutional cumulative follow-up study

The aim of this retrospective study was to establish the prognostic factors for overall survival after pulmonary resection for lung metastases of colorectal carcinoma (CRC). The baseline characteristics and outcomes of 266 CRC patients undergoing complete pulmonary resection were collected from 19 institutions by the Japanese Society for Cancer of the Colon and Rectum (JSCCR) Study Group. We used the Cox proportional hazard regression to identify independent prognostic factors for OS. The 5-year overall survival rate of patients undergoing complete resection of isolated pulmonary metastases was 56.5 %. The independent unfavorable prognostic factors after pulmonary resection included stage T4 (p = 0.0004) and N2 (p = 0.0082) as primary cancer-related factors, and more than three metastases (p = 0.0342), bilateral distribution (p = 0.0450), metastatic disease-free interval (DFI) of less than 2 years (p = 0.0257), and a preoperative carcinoembryonic antigen (CEA) level greater than 5.0 ng/mL (p = 0.0209) as pulmonary metastases-related factors. This retrospective analysis suggested that the indications for pulmonary resection of CRC metastases should be decided not only by the status of lung metastases, but also by pulmonary-related factors such as the T and N stage of the primary lesion, preoperative CEA level, and the DFI.

Surgery of Pulmonary Metastases: Series of 85 Patients

Introduction: Lung metastases are the second leading cause of lung resection, constituting 30-40% of all surgeries performed in the field of Thoracic Surgery. Resection of pulmonary metastases is an open issue that generates various controversies. Depending on the functional respiratory capacity of the pulmonary metastatic patient, may come to consider multiple surgeries in the same patient, as many as the patient is able to tolerate by his or her respiratory reserve. Goal: Study of the results from surgical resection of pulmonary metastases in general and in particular those of colorectal origin. Patients and methods: Descriptive and observational retrospective study of 85 patients with pulmonary metastases who underwent surgery at our centre from January 2003 to December 2007. Results: Surgery was performed in 85 patients, 56 males (66%) and 29 women (34%) with a mean age of 55.14 years (range 22-82 years). The PMCRC (Pulmonary Metastases from Colorectal Cancer) correspond to 30 patients, meaning a 35% of all resected metastases. Next in frequency were the lung metastases of osteosarcoma, 16 (19%). And really close, metastases of soft tissue sarcoma, 11 (13%). The average overall survival from PM (Pulmonary Metastases) of colorectal origin was 36.64 months (range 18.58 to 54.70 months). If we break down the overall survival at one and three years, we get a probability of survival of 96% compared to 62%. Conclusions: Although surgery cannot change the biological essence of the metastatic process, complete resection of pulmonary metastases in appropriated selected patients, can provide a significant increase in survival or even a complete and permanent remission of the tumor.

Pulmonary metastasectomy: a multivariate analysis of 440 patients undergoing complete resection

Surgical resection is currently a standard approach for isolated lung metastases from different primary tumours. The aim of the present analysis is to evaluate the outcome of patients submitted to complete resection of pulmonary metastases and to determine prognostic factors for long-term survival. A group of 440 consecutive patients previously diagnosed with primary malignant solid tumours and submitted to complete surgical resection of lung nodules with suspected or diagnosed metastatic lesion were retrospectively reviewed. The average follow-up time was 43.2 months (range: 0-192) and the 60-month O.S. was 43.7%. Univariate analysis: patients with adenocarcinoma presented the highest 5-year survival rates (53.4%, P = 0.0001); DFI >36 months (P < 0.0001), number of nodules on CT scan (P = 0.0052), number of malignant nodules resected (P = 0.0252) and the size of the largest resected nodule (P < 0.0001) were also significant. Multivariate analysis: number of malignant nodules resected (P = 0.01), size of the largest nodule resected (P = 0.001), DFI >36 months (P < 0.001) and histology of the primary tumour (P = 0.017) had significant impact on survival. The benefit of such an aggressive surgical approach is only limited to selected subgroups of patients. The decision to consider a patient for resection of metastastic disease should include factors beyond the feasibility of complete removal.

Growth patterns of lung metastases from sarcomas

Complete resection of pulmonary metastases from sarcomas is an established method of treatment. While resection margins are well described for primary sarcoma lesions, minimal knowledge is available about margins and factors influencing local tumour control in the lung. The objective of the present study was to describe intrapulmonary patterns of growth for sarcoma metastases as a basis for planning resections. From January 2006 to January 2009, we retrospectively analysed 261 resected pulmonary sarcoma metastases from 52 patients. All metastases were reviewed for histological characteristics and resection margins. Metastases characterised by a solid, well-defined tumour mass were found in 127 of 261 metastases (48.7%). Interstitial spread (39.8%), vascular infiltration (20.7%), satellite nodules (16.1%) and lymphangitic spread (10.7%) were identified as aggressive histological growth characteristics. Forty-five of 52 patients (86.5%) had metastases with a mitotic index of 10 or more per 10 HPF, underlining their high-grade malignant potential. The following characteristics of aggressive intrapulmonary growth were highly correlated with each other: interstitial growth and lymphangitic spread (p = 0.002), interstitial growth and vascular infiltration (p < 0.001), vascular infiltration and satellite nodules (p = 0.009), interstitial growth and pleural invasion (p = 0.004); by contrast, the presence of a fibrous pseudocapsule (17.2%) was not associated with aggressive growth patterns. Almost half of all pulmonary sarcoma metastases could be identified with aggressive patterns of local growth, and only 17.2% are surrounded by a pseudocapsule which might allow safe resection margins.

Complete Resection of Pulmonary Metastatic Melanoma

BackgroundThe prognosis of melanoma metastasized to other organs is very poor. There have been many studies on metastatic melanoma in Western society, but there have been few studies done in Korea because of the small number of cases.Materials and MethodsA retrospective review of 7 patients who underwent complete resection of pulmonary metastases from melanoma from January 2005 to December 2009 was performed. When the primary lesion was controlled or simultaneously controllable and no other metastatic lesion was found, pulmonary resections were performed. We analyzed the clinical prognoses after the initial melanoma diagnosis.ResultsOf the seven patients, one was male and six were female. The mean age was 58.2 years (range 45~71). Six patients had a single pulmonary lesion and one patient had three lesions confined to the same lobe. The mean disease-free interval was 43.5 months (0~146 months). Before pulmonary resection, 4 patients had received systemic therapy. After pulmonary resection, 6 patients received systemic therapy. Complete resection was confirmed histologically. The metastasectomy was performed by wedge resection (6 patients) or lobectomy (1 patient). There were no mortalities or complications. After pulmonary resection, 1 patient had recurrent multiple lesions in the lung and 4 patients had metastases to other organs. The organs were the liver, brain, pleura, and lymph nodes. The mean observation time was 31.6 months and 3 patients died during observation. The mean survival was 27.7 months (14~60 months) and the 1-year and 3-year survival rates were 100% and 42%, respectively.ConclusionWhen patients were selected carefully, the complete resection of pulmonary metastatic lesions was considered a major therapeutic tool.

Survival after Pulmonary Metastasectomy in Patients with Malignant Melanoma

Surgical resection is an important interdisciplinary treatment for pulmonary metastases of metastatic malignant melanoma. The purpose of this study was to determine the clinical course, outcome and prognostic factors in a subset of patients recently treated by metastasectomy. Between 1995 and 2007, 30 patients (19 men, 11 women) with pulmonary metastases from malignant melanoma underwent pulmonary resection. Exclusion of primary tumor recurrence and other extrapulmonary metastases was mandatory for inclusion in the study. The median follow-up was 93.7 months. These patients' records were subsequently reviewed. Cumulative 5-year survival rate after pulmonary resection was 35.1% with a median survival of 18.3 months. Complete pulmonary resection was achieved in 27 patients who had a median survival of 20.5 months compared to 13.0 months after incomplete resection; however, completeness of resection was not a statistically prognostic factor for survival. Multivariate analysis identified gender as the only significant prognostic parameter for overall survival in the group of patients after complete resection of pulmonary metastases, with 9.4 months versus 25.0 months for the female and male group, respectively ( P = 0.022). We conclude that pulmonary metastasectomy for metastases of malignant melanoma is a safe treatment modality which may actually be of benefit in selected patients with stage IV malignant melanoma. When pulmonary metastases of malignant melanoma are present, every attempt should be made to completely resect all clinically detected metastases.

Hand-Assisted Thoracoscopic Surgery for Bilateral Lung Metastasectomy Through Sternocostal Triangle Access

Complete resection of pulmonary metastases remains the standard of care for selected patients. An open approach causes criticism because of aggressiveness. Without manual palpation the video-assisted thoracic surgery procedure has the high probability of missing occult metastases. Transxiphoid bilateral lung metastasectomy surgery has not been widely adopted. We developed a hand-assisted thoracoscopic surgery for bilateral lung metastasectomy through natural sternocostal triangle access in 2001 to solve the problems mentioned previously. We retrospectively evaluated 55 consecutive patients between 2001 and 2009 who underwent hand-assisted thoracoscopic surgery through sternocostal triangle access for pulmonary metastasis. Complications after operation, operative time, operative bleeding, air leak days, length of stay, preoperation imaging examination, and survival rate were evaluated. Fifty-five patients had lung metastases. Bilateral explorations were performed in a total of 51 patients, with a total of 201 minimal resections and one lobectomy. Nearly half of the patients with bilateral metastases were misdiagnosed as unilateral metastases by imaging examination. Intraoperative cardiac arrhythmia was experienced in 5.2% of the right and 10.5% of the left approaches. Postoperative complication rate was 3.6%. Three-year and five-year overall survival rates for metastatic disease were 59.8% and 47.2%, respectively. This new surgical procedure, with an assisted hand, could complete bilateral pleural exploration in a single operation through the natural sternocostal triangle. It is easy to perform and may help the patients gain a faster rehabilitation. Furthermore, it may lead to a better survival.

Author's reply: Factors influencing survival after complete resection of pulmonary metastases from colorectal cancer (Br J Surg 2009; 96: 1058–1065)

Author's reply: Factors influencing survival after complete resection of pulmonary metastases from colorectal cancer (<i>Br J Surg</i> 2009; 96: 1058–1065)

Factors influencing survival after complete resection of pulmonary metastases from colorectal cancer (Br J Surg 2009; 96: 1058–1065)

Factors influencing survival after complete resection of pulmonary metastases from colorectal cancer (<i>Br J Surg</i> 2009; 96: 1058–1065)

Factors influencing survival after complete resection of pulmonary metastases from colorectal cancer

The aim of this retrospective study was to determine the efficacy of complete (R0) resection for pulmonary metastases of colorectal carcinoma, and to clarify prognostic factors for survival that could be used to identify patients likely to benefit most from pulmonary resection. Data on 113 patients who underwent R0 resection of pulmonary metastases from colorectal cancer were reviewed. Overall median follow-up was 49 (range 1-140) months. Clinical and pathological factors were reviewed, and prognostic factors influencing survival were identified. The overall 5-year survival rate was 67.8 per cent. Multivariable Cox hazard regression analysis revealed that the prethoracotomy serum carcinoembryonic antigen (CEA) level and lymphatic invasion by pulmonary tumour correlated significantly with survival. The 5- and 7-year survival rates of patients with a prethoracotomy CEA level below 5 ng/ml and no lymphatic invasion by pulmonary tumour were 94 and 79 per cent respectively. Pathological features of the primary colorectal cancer, previous hepatectomy for liver metastasis and repeated thoracotomy had no impact on survival. Long-term survival can be expected after R0 resection of pulmonary metastases from colorectal cancer, particularly in patients with a prethoracotomy CEA level below 5 ng/ml and no lymphatic invasion by pulmonary tumour.

Diagnosis of Pulmonary Metastases with Helical CT: The Effect of Imaging Techniques

Survival in patients after surgical resection of pulmonary metastases correlates with the complete resection of all metastatic deposits. The purpose of this study was to evaluate the additional value of helical CT to see whether the slice thickness and the reading environment was a factor determining the accuracy of helical scans. Between 2004 and 2007, 93 patients (62 men, 31 women) underwent complete resection of pulmonary metastases by open thoracotomy. A total of 125 thoracotomies were performed with manual palpation of the involved lung. We retrospectively examined the helical CT findings obtained using a 5-mm slice thickness in a routine preoperative analysis, and within this study a second reading was performed independently, using 3-mm slice thickness image sets. The CT images were evaluated in a consensus between two radiologists. Computed tomography scanning was performed a median of 12 days before thoracotomy (range 1-121 days). Analysis of helical CT in 5-mm slice thickness detected metastases with a sensitivity of 83.7 % whereas a 3-mm slice thickness had a sensitivity of 88.8 %. There were statistically significantly more lesions using helical CT and a 3-mm slice thickness technique than with the 5-mm slice thickness technique, compared to the surgical results ( P = 0.002). This was also found with regard to nodules which were finally histologically confirmed as lung metastases ( P = 0.014). We conclude that a reduced slice thickness may have an important positive impact on the treatment and outcome of patients with pulmonary metastases. The use of 3-mm slice thickness helical CT may raise the sensitivity for pulmonary metastases detection compared to 5-mm images, but the rate of false positive results may also increase.

Resection of pulmonary metastases from colorectal carcinoma

Although pulmonary metastases from colorectal carcinoma (CRC) often represent systemic and uncontrolled tumour growth, in a number of patients lung disease is limited and the patient remains well. When the metastases can be removed, long term survival is a possibility, with 5- and 10-year survivals in the order of 44% and 25%. Chemotherapy, the only alternative treatment only very rarely leads to survival beyond 24 months. Pulmonary metastases which are suitable for resection are usually detected on chest radiography, especially when carried out during monitoring of patients. They are rarely a cause of symptoms and the majority of patients have otherwise healthy lungs. CT scans supplemented by PET scans usually confirm the diagnosis, but percutaneous biopsy is sometimes necessary to exclude a primary lung cancer. The criteria for resecting CRC pulmonary metastases are (1) the primary tumour is controlled or is controllable; (2) complete resection is possible; and (3) the patient has adequate pulmonary reserve to tolerate the planned resection. Surgical approaches include posterolateral thoracotomy, staged bilateral thoracotomies, median sternotomy, clamshell incision, and video-assisted thoracic surgery. Each has its advantages and disadvantages. The majority of patients having resection of pulmonary metastases from CRC recover well with very few post-operative complications. Following resection favourable prognostic factors include a long disease-free interval, small number and small size of metastases, a normal carcinoembryonic antigen level, and an absence of concomitant liver metastases and mediastinal lymph node spread. Surgery for pulmonary metastases of CRC remains the best means of local control and the best way to render the patient disease-free. Patients with complete resection of pulmonary metastases have an improved long-term survival when compared to patients with unresected metastases.

Two-Year Survival After Multiple Bilateral Lung Metastasectomies for Cranial Meningioma

The lung represents a common site of metastases from extrathoracic malignancies, and several studies have strengthened the evidence that complete resection of pulmonary metastases is a useful therapeutic treatment for prolonged survival in selected patients. However, fewer data are available in the literature regarding the role of lung metastasectomy in rare malignancy. We present a case of extensive bilateral lung metastases due to recurrent cranial meningioma, which was successfully treated by aggressive, staged metastasectomies.

Histopathologic Prognostic Factors in Resected Colorectal Lung Metastases

Pulmonary metastasectomy is a standard method of treatment for selective pulmonary metastases of colorectal cancer. However, the pathologic factors of metastatic lesions that affect survival and tumor recurrence after pulmonary resection are less well defined. The pathologic findings of colorectal pulmonary metastases have not been correlated with clinical outcome. The study was conducted to clarify the characteristics and identify the prognostic factors of the pulmonary metastases of colorectal cancer. Between July 1992 and November 2002, 89 patients underwent the complete resection of pulmonary metastases of primary colorectal carcinoma, and we pathologically reviewed the surgical specimens of 136 metastatic lesions from these patients. There were no perioperative deaths. The overall 5-year survival rate was 61.4%. No clinical factors were associated with the outcome. The univariate analysis of pathologic factors revealed aerogenous spread with floating cancer cell clusters (ASFC) (p = 0.004), vascular invasion (p = 0.002), lymphatic invasion (p = 0.032), and pleural invasion (p = 0.037) to be prognostic factors. The multivariate analysis showed vascular invasion (p = 0.02) and ASFC (p = 0.02) to be independent prognostic factors. The 5-year survival rate of patients whose lesions were positive for both ASFC and vascular invasion was 24.7% and much poorer than in the patients with ASFC without vascular invasion (78.6%), vascular invasion but without ASFC (80.2%), and patients negative for both (93.3%) (p = 0.0002). The morphologic features of ASFC and vascular invasion at metastatic sites are prognostic factors for colorectal cancer patients who have undergone pulmonary metastasectomy.