2115: Isolated Lymph Node Metastasis From Colorectal Cancer Treated by Stereotactic Radiation Therapy

Abstract

Purpose/Objective(s)Although metastases from primary tumors are usually considered to be fatal, the patients with isolated metastases from colorectal cancers can be expected to have a relatively long survival if treatment is performed adequately. As treatment for isolated liver or lung metastasis from colorectal cancer, the role of aggressive local modality like surgery was defined well. However, in cases of isolated lymph node (LN) metastasis, the role of local modality was not defined exactly and chemotherapy was considered for the only treatment option. The aim of this study is to evaluate the role of stereotactic radiation therapy (SRT) as local modality treatment for isolated lymph node metastasis from colorectal cancer.Materials/MethodsFrom September 2002 to August 2004, among 42 patients with recurrent colorectal cancer treated with SRT using CyberKnife (CK), 19 patients were proven to have isolated LN metastasis and enrolled for this retrospective analysis. They all received chemotherapy as first line or combined with CK. The recurrence sites were pelvic LN in 10 patients, presacral or rectal lesion in 6, and periaortic LN in 3. Four patients received previous RT on treatment site. The patients who were in the status of first and second relapse at the time for CK were 16 and 3, respectively. The range of the longest diameter of the tumor was 2–11 cm (median 4 cm). Four patients were treated with a single fraction of 13 to 18 Gy as a boost following external beam radiation therapy (RT) of 40 to 45 Gy. Fifteen patients received 3 fraction SRT of 33 Gy to 42 Gy. Overall survival (OS), tumor progression-free survival (TPFS) and disease progression-free survival (DPFS) rate were calculated from the date of SRT using Kaplan-Meier method. The median follow-up duration was 26 months (range 7–39 months).ResultsThe 3-year OS rate was 67.5% and DPFS rate was 45%. The overall median survival time was 37 months. Tumor response evaluated by 12 months after CK were complete response (CR) in 9 patients (47%), partial response (PR) in 3 patients (16%), stable disease (SD) in 6 patients (32%), and progression (PD) in 1 patient. The cases with first relapse, smaller planning target volume (≤26 cc), or long progression free time from operation to first relapse (>23 months) had significant better OS (p<0.05). Also response group (CR+PR) after CK had significant better OS (p=0.06) than that of non-response group (SD+PD). In aspect of TPFS, the cases that first relapse occurred within 24 months after initial operation had significant poor prognosis (p<0.05). The diameter of tumor (≤4.5 cm vs. >4.5 cm) was marginally significant factor on DFS (p=0.07). Treatment related severe complication was not found during follow-up period.ConclusionsEven though follow-up period is not enough to evaluate its effectiveness, the OS or DFS rate were outstanding and showed similar to the results of cases performed surgery for isolated liver or lung metastasis. Isolated LN metastasis from colorectal cancer would be good candidate for aggressive local modality including SRT in aspect of improving survival rate as cases of isolated lung or liver metastasis. Purpose/Objective(s)Although metastases from primary tumors are usually considered to be fatal, the patients with isolated metastases from colorectal cancers can be expected to have a relatively long survival if treatment is performed adequately. As treatment for isolated liver or lung metastasis from colorectal cancer, the role of aggressive local modality like surgery was defined well. However, in cases of isolated lymph node (LN) metastasis, the role of local modality was not defined exactly and chemotherapy was considered for the only treatment option. The aim of this study is to evaluate the role of stereotactic radiation therapy (SRT) as local modality treatment for isolated lymph node metastasis from colorectal cancer. Although metastases from primary tumors are usually considered to be fatal, the patients with isolated metastases from colorectal cancers can be expected to have a relatively long survival if treatment is performed adequately. As treatment for isolated liver or lung metastasis from colorectal cancer, the role of aggressive local modality like surgery was defined well. However, in cases of isolated lymph node (LN) metastasis, the role of local modality was not defined exactly and chemotherapy was considered for the only treatment option. The aim of this study is to evaluate the role of stereotactic radiation therapy (SRT) as local modality treatment for isolated lymph node metastasis from colorectal cancer. Materials/MethodsFrom September 2002 to August 2004, among 42 patients with recurrent colorectal cancer treated with SRT using CyberKnife (CK), 19 patients were proven to have isolated LN metastasis and enrolled for this retrospective analysis. They all received chemotherapy as first line or combined with CK. The recurrence sites were pelvic LN in 10 patients, presacral or rectal lesion in 6, and periaortic LN in 3. Four patients received previous RT on treatment site. The patients who were in the status of first and second relapse at the time for CK were 16 and 3, respectively. The range of the longest diameter of the tumor was 2–11 cm (median 4 cm). Four patients were treated with a single fraction of 13 to 18 Gy as a boost following external beam radiation therapy (RT) of 40 to 45 Gy. Fifteen patients received 3 fraction SRT of 33 Gy to 42 Gy. Overall survival (OS), tumor progression-free survival (TPFS) and disease progression-free survival (DPFS) rate were calculated from the date of SRT using Kaplan-Meier method. The median follow-up duration was 26 months (range 7–39 months). From September 2002 to August 2004, among 42 patients with recurrent colorectal cancer treated with SRT using CyberKnife (CK), 19 patients were proven to have isolated LN metastasis and enrolled for this retrospective analysis. They all received chemotherapy as first line or combined with CK. The recurrence sites were pelvic LN in 10 patients, presacral or rectal lesion in 6, and periaortic LN in 3. Four patients received previous RT on treatment site. The patients who were in the status of first and second relapse at the time for CK were 16 and 3, respectively. The range of the longest diameter of the tumor was 2–11 cm (median 4 cm). Four patients were treated with a single fraction of 13 to 18 Gy as a boost following external beam radiation therapy (RT) of 40 to 45 Gy. Fifteen patients received 3 fraction SRT of 33 Gy to 42 Gy. Overall survival (OS), tumor progression-free survival (TPFS) and disease progression-free survival (DPFS) rate were calculated from the date of SRT using Kaplan-Meier method. The median follow-up duration was 26 months (range 7–39 months). ResultsThe 3-year OS rate was 67.5% and DPFS rate was 45%. The overall median survival time was 37 months. Tumor response evaluated by 12 months after CK were complete response (CR) in 9 patients (47%), partial response (PR) in 3 patients (16%), stable disease (SD) in 6 patients (32%), and progression (PD) in 1 patient. The cases with first relapse, smaller planning target volume (≤26 cc), or long progression free time from operation to first relapse (>23 months) had significant better OS (p<0.05). Also response group (CR+PR) after CK had significant better OS (p=0.06) than that of non-response group (SD+PD). In aspect of TPFS, the cases that first relapse occurred within 24 months after initial operation had significant poor prognosis (p<0.05). The diameter of tumor (≤4.5 cm vs. >4.5 cm) was marginally significant factor on DFS (p=0.07). Treatment related severe complication was not found during follow-up period. The 3-year OS rate was 67.5% and DPFS rate was 45%. The overall median survival time was 37 months. Tumor response evaluated by 12 months after CK were complete response (CR) in 9 patients (47%), partial response (PR) in 3 patients (16%), stable disease (SD) in 6 patients (32%), and progression (PD) in 1 patient. The cases with first relapse, smaller planning target volume (≤26 cc), or long progression free time from operation to first relapse (>23 months) had significant better OS (p<0.05). Also response group (CR+PR) after CK had significant better OS (p=0.06) than that of non-response group (SD+PD). In aspect of TPFS, the cases that first relapse occurred within 24 months after initial operation had significant poor prognosis (p<0.05). The diameter of tumor (≤4.5 cm vs. >4.5 cm) was marginally significant factor on DFS (p=0.07). Treatment related severe complication was not found during follow-up period. ConclusionsEven though follow-up period is not enough to evaluate its effectiveness, the OS or DFS rate were outstanding and showed similar to the results of cases performed surgery for isolated liver or lung metastasis. Isolated LN metastasis from colorectal cancer would be good candidate for aggressive local modality including SRT in aspect of improving survival rate as cases of isolated lung or liver metastasis. Even though follow-up period is not enough to evaluate its effectiveness, the OS or DFS rate were outstanding and showed similar to the results of cases performed surgery for isolated liver or lung metastasis. Isolated LN metastasis from colorectal cancer would be good candidate for aggressive local modality including SRT in aspect of improving survival rate as cases of isolated lung or liver metastasis.