Impact of stereotactic body radiotherapy on colorectal cancer with distant metastases

Neoadjuvant chemotherapy and radiotherapy followed by resection/ablation in stage IV rectal cancer patients with potentially resectable metastases

Background

The optimal treatment of stage IV rectal cancer remains controversial. The purpose of this study was to assess the treatment outcomes and toxicity of neoadjuvant chemotherapy and radiotherapy followed by local treatment of all tumor sites and subsequent adjuvant chemotherapy in stage IV rectal cancer patients with potentially resectable metastases.

Methods

Adult patients diagnosed with locally advanced rectal adenocarcinoma with potentially resectable metastases, who received neoadjuvant chemotherapy and radiotherapy from July 2013 and September 2019 at Sun Yat-sen University cancer center, were included. Completion of the whole treatment schedule, pathological response, treatment-related toxicity and survival were evaluated.

Results

A total of 228 patients were analyzed with a median follow-up of 33 (range 3.3 to 93.4) months. Eventually, 112 (49.1%) patients finished the whole treatment schedule, of which complete response of all tumor sites and pathological downstaging of the rectal tumor were observed in three (2.7%) and 90 (80.4%) patients. The three-year overall survival (OS) and progression-free survival (PFS) of all patients were 56.6% (50.2 to 63.9%) and 38.6% (95% CI 32.5 to 45.8%), respectively. For patients who finished the treatment schedule, 3-year OS (74.4% vs 39.2%, P < 0.001) and 3-year PFS (45.5% vs 30.5%, P = 0.004) were significantly improved compared those who did not finish the treatment. Grade 3–4 chem-radiotherapy treatment toxicities were observed in 51 (22.4%) of all patients and surgical complications occurred in 22 (9.6%) of 142 patients who underwent surgery, respectively.

Conclusions

Neoadjuvant chemotherapy and radiotherapy followed by resection/ablation and subsequent adjuvant chemotherapy offered chances of long-term survival with tolerable toxicities for selected patients with potentially resectable stage IV rectal cancer, and could be considered as an option in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09089-5.

We need to bring R0 < 1 to treat cancer too

If each cancer cell produces on average more than one cancer cell, we see a net growth of the tumors and metastases and vice versa. We review recent clinical results for microsatellite stable metastatic colorectal cancer (MSS-mCRC) suggesting immunotherapy combinations with personalized vaccines, checkpoint inhibitors, targeted therapies, multikinase inhibitors, chemotherapies, and radiation that simultaneously slow cancer cell growth rate and enhance T cell killing rate of cancer cells may in future synergize to control the disease.

A Pilot Study of the PD-1 Targeting Agent AMP-224 Used With Low-Dose Cyclophosphamide and Stereotactic Body Radiation Therapy in Patients With Metastatic Colorectal Cancer

BACKGROUND

The prognosis of metastatic colorectal cancer (mCRC) is poor. We assessed the feasibility, safety, and efficacy of the anti-programmed cell death 1 fusion protein AMP-224 in combination with low-dose cyclophosphamide and stereotactic body radiation (SBRT) treatment in patients with mCRC refractory to standard chemotherapy.

PATIENTS AND METHODS

Fifteen patients were enrolled. Six received SBRT 8 Gy on day 0 (dose level 1), whereas 9 received 8 Gy on days -2 to day 0. All received cyclophosphamide 200 mg/m² intravenously (I.V.) on day 0. On day 1, both groups received AMP-224 10 mg/kg I.V., repeated every 2 weeks for a total of 6 doses. Primary end points were feasibility and safety.

RESULTS

Ten (67%) patients completed 6 doses of AMP-224; 5 patients (33%) discontinued treatment because of disease progression. No dose-limiting toxicity was observed; 9 patients (60%) experienced treatment-related adverse events, all Grade 1 or 2. No objective response was noted; 3 patients (20%) had stable disease. Median progression-free survival and overall survival were 2.8 months (95% confidence interval [CI], 1.2-2.8 months) and 6.0 months (95% CI, 2.8-9.6 months), respectively. M2 macrophage polarization was present in the pretreatment tumor biopsy samples, but not post-treatment samples.

CONCLUSION

AMP-224 in combination with SBRT and low-dose cyclophosphamide was well tolerated, however, no significant clinical benefit was observed in patients with mCRC.

Application of stereotactic body radiation therapy to cancer liver metastasis

As an accurate external beam irradiation method, stereotactic body radiotherapy (SBRT) has been increasingly used to deliver high dose in less fractions. The liver is one of the most common organs for cancer metastasis. Recently, there have been several trials applying SBRT to cancer liver metastasis and have proved to be effective and safe with local control (LC) rates ranging from 70% to 100% within one or two years and 2-year overall survival (OS) rates ranging from 30% to 38%. Many published studies indicate that SBRT for cancer liver metastasis results in good outcomes without severe toxicities. However, the validated contribution of SBRT to an improved progression-free survival is still missing and more randomized trials should be conducted.

Lung Metastases Treated With Stereotactic Ablative Radiation Therapy in Oligometastatic Colorectal Cancer Patients: Outcomes and Prognostic Factors After Long-Term Follow-Up

BACKGROUND

We evaluated a series of oligometastatic colorectal cancer (CRC) patients treated with stereotactic ablative body radiotherapy (SABR) delivered in all active lung metastases.

PATIENTS AND METHODS

Forty-four patients with 69 lung metastases were treated with SABR. Eleven patients presented with other sites of metastases before stereotactic body radiotherapy (SBRT), even though they had controlled/cured systemic disease.

RESULTS

The median follow-up was 36 months. The median overall survival (OS) was 38 months and 2 years, 3-year OS rates were 67.7% and 50.8%, respectively. The median progression-free survival (PFS) was 10 months and 2 years, 3-year PFS rates were 20.3% and 16.2%, respectively. Local recurrence occurred in 16 patients (36%).The first site of failure was local only in 22%, distant only in 35%, and local and distant in 14% of the patients. The 1-year, 2-year, and 3-year local PFS (LPFS) were 68.8%, 60.2%, and 54.2%, respectively. No Grade ≥ 3 toxicities were recorded in the univariate analysis; multiple lung metastases and synchronous oligometastatic disease were significantly associated with worse PFS (P = .04, and P < .001, respectively) and worse metastases-free survival (MFS; P = .04, and P < .001, respectively). The type of response was identified as a significant prognostic factor for OS (P = .014), PFS (P = .006), and LPFS (P < .001). In multivariate analysis single lung metastases treated with SBRT was associated with better MFS (P = .015). Metachronous oligometastatic disease and type of response were associated with significantly better PFS.

CONCLUSION

Stereotactic body radiotherapy is a valid therapy in the treatment of lung metastases for oligometastatic CRC patients presenting long survival. The rate of local control remains lower compared with other primaries. Further prospective cohorts would better evaluate effective fractionation for patients with oligometastatic CRC.

Liver-directed therapies in metastatic colorectal cancer

Colorectal cancer (CRC) is a major health concern in the United States (US) with over 140,000 new cases diagnosed in 2012. The most common site for CRC metastases is the liver. Hepatic resection is the treatment of choice for colorectal liver metastases (CLM), with a 5-year survival rate ranging from 35% to 58%. Unfortunately, only about 20% of patients are eligible for resection. There are a number of options for extending resection to more advanced patients including systemic chemotherapy, portal vein embolization (PVE), two stage hepatectomy, ablation and hepatic artery infusion (HAI). There are few phase III trials comparing these treatment modalities, and choosing the right treatment is patient dependent. Treating hepatic metastases requires a multidisciplinary approach and knowledge of all treatment options as there continues to be advances in management of CLM. If a patient can undergo a treatment modality in order to increase their potential for future resection this should be the primary goal. If the patient is still deemed unresectable then treatments that lengthen disease-free and overall-survival should be pursued. These include chemotherapy, ablation, HAI, chemoembolization, radioembolization (RE) and stereotactic radiotherapy.