Neutrophil-to-lymphocyte ratio for the prediction of soft tissue sarcomas response to pre-operative radiation therapy

PURPOSE/OBJECTIVE

This study aims to assess the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in soft tissue sarcomas (STS) treated with pre-operative hypofractionated radiotherapy (HFRT).

MATERIALS/METHODS

This retrospective analysis included patients treated with pre-operative HFRT of 30 Gy in 5 fractions between 2016 and 2023. Clinical, demographic, and complete blood count (CBC) data were collected. NLR was calculated by dividing the absolute neutrophil count by the absolute lymphocyte count. Only patients with CBCs conducted within 6 months after radiotherapy were included. Cox proportional-hazard regression models were used to assess the impact of NLR and different variables on outcomes. Kaplan Meier were used to illustrate survival curves. A p-value < 0.05 was considered significant, and 95 % confidence intervals (CI) were employed.

RESULTS

A total of 40 patients received HFRT and had CBCs within 6 months after radiotherapy. There were 17 (42.5 %) females and 23 (57.5 %) males with a mean age of 66 years. The mean largest tumor size dimension was 7.1 cm, and the mean NLR post-RT was 5.3. The most frequent histological subtypes were myxofibrosarcoma (17.5 %), pleomorphic spindle cell sarcoma (10 %), leiomyosarcoma (7.5 %), and myxoid liposarcoma (5 %). The median follow-up period was 15.4 months. From all patients, 14 patients had disease progression, 12 metastatic disease and 3 died of disease. Multivariable Cox proportional-hazards regression analysis displayed that a higher post-RT NLR was associated with worse disease-free survival (DFS) (HR: 1.303 [1.098-1.548], p = 0.003), and distant metastasis-free survival (DMFS) (HR: 1.38 [1.115-1.710], p = 0.003). Moreover, post-NLR ≥ 4 as a single variable was associated with worse DFS, DMFS, but not worse local recurrence or overall survival.

CONCLUSION

This study is the first to evaluate NLR as a prognostic biomarker in STS patients treated with pre-operative radiotherapy. A higher NLR after pre-operative radiotherapy was associated with increased disease progression.

Hypofractionated Preoperative Radiotherapy 30Gy in Five Fractions for Soft Tissue Sarcoma of the Extremity

PURPOSE/OBJECTIVE(S)

Hypofractionated preoperative radiotherapy (HypoRT) is being used with increasing frequency for soft tissue sarcomas (STS) of the extremities. Besides the social and economic advantages, HypoRT has a theoretical advantage in STS because of their low α/β ratio. The objective of this study is to review our experience using HypoRT to a dose of 30Gy in 5 fractions in STS of the extremities.

MATERIALS/METHODS

This study is a retrospective review of patients with extremity STS treated at our center with preoperative HypoRT to a dose of 30Gy in 5 fractions given on alternate days over 2 weeks. Inclusion criteria were age ≥18 years, biopsy-proven primary STS in an extremity, and fitness for surgery. The primary endpoint was major wound complications (MWC) defined as the need for wound management or secondary operation under general or regional anesthesia within 120 days from surgery. Secondary objectives were: early toxicity grade ≥ 2 and clinical outcomes, including local control (LC), and metastasis-free survival (MFS). Descriptive statistics were used to evaluate patient and treatment characteristics. The Kaplan-Meier method was used to estimate survival.

RESULTS

A total of 40 patients received preoperative HypoRT at our center between 2016 and 2022. The median age was 70 years (30 - 91). Males accounted for 57.5% of the patients. The most common primary site was the lower extremity (62.5%). The most prevalent histologic type was myxofibrosarcoma (27.5%), followed by pleomorphic spindle cell sarcoma (20%). All patients were treated with image-guided intensity modulated radiotherapy with margins for the CTV as tested in the RTOG 0630 study. Median follow-up was 14.8 months (5 - 86). Acute side effects were seen in 80% of the patients, all grade <3. The most common toxicity was dermatitis (37.5%), the second was fatigue (20%), and the third was pain (15%). Surgery was performed in all cases after a median interval from completion of HypoRT of 34 days (16-59). Amputation was performed in one patient with a fungating tumor, HypoRT having been aborted at only 24Gy because of worsening symptoms. On pathologic examination, positive margins were found in four cases (10%). The percentage of necrosis was ≥ 90% in 7 patients and 50%-90% in 10. MWC occurred in 13 patients (32.5%), including 10 who underwent a procedure with anesthesia. Sixteen patients were treated for a wound infection. Only one patient recurred locally. Two-year LC was 91.7%. MFS was 87.4% at 6 months and 60.8% at 2 years. DFS was 84.9% at 6 months and 64.8% at 2 years.

CONCLUSION

The preoperative HypoRT regimen of 30Gy in 5 fractions given on alternate days for extremity STS is safe. Acute toxicity was not different from our previous experience using the conventional regimen of 50Gy in 25 fractions over 5 weeks and the MWC rate was comparable to that reported for the conventional regimen. Local control was excellent.

Post-Hypofractionated Radiotherapy Neutrophil-to-Lymphocyte Ratio in Soft Tissue Sarcomas is a Prognostic Biomarker of Recurrence and Distant Metastases

PURPOSE/OBJECTIVE(S)

The neutrophil-to-lymphocyte ratio (NLR) is a measure of systemic inflammation, and known to be prognostic of outcomes and treatment response across different cancer types, including soft tissue sarcomas (STS). Our study aims to determine if in patients with STS treated with pre-operative hypofractionated radiotherapy (HFRT), post-RT NLR is prognostic of recurrence, metastasis, and overall survival.

MATERIALS/METHODS

We performed a single-center retrospective analysis of patients treated pre-operatively with 30 Gy in 5 fractions between 2016 and 2023. Clinical, demographic, radiation therapy (RT), and complete blood count (CBC) data were collected from medical records. The NLR calculation was performed by dividing the absolute neutrophils count by the absolute lymphocytes count. We dichotomized the variable into NLR ≤4 and >4. The CBC utilized to calculate NLR was only used if done <6 months post-RT. For post-RT NLR outcomes associations, we used univariable and multivariable logistic regression analyses adjusting for age, gender, tumor size, and histology. For continuous variables we used mean ± standard deviation. Analyses were done with SPSS. A p-value <0.05 was considered significant.

RESULTS

We identified 40 patients that received HFRT and had a CBC within 6 months after RT. The mean age was 66 ± 17.5 years. There were 17 (42.5%) females and 23 (57.5%) males. The histologies were myxofibrosarcoma (17.5%), leiomyosarcoma (7.5%), pleomorphic spindle cell sarcoma (10%), myxoid liposarcoma (5%). Other histologies with n<2 accounted for 65%. The mean tumor size was 7.1cm (± 6.4) and the mean NLR 5.3 ± 0.6. The median follow-up was 15.4 ±2.2 months. The patients with recurrence and metastases were the same {n = 13 (32.5%)}, and 3 patients died of disease. Univariable analyses for NLR > 4 showed increased recurrence and metastases (Odds ratio (OR): 8, CI 95% = {1.48 - 43.4}, p = 0.016). The multivariable analyses also showed that post-RT NLR > 4, was associated with increased recurrence and metastases (OR: 7.73, CI 95% = {1.17- 50.9}, p- value = 0.034). Age, gender, histology, and tumor size were not significant variables (Table 1). In both univariable and multivariable analyses NLR > 4 was not associated with decreased overall survival (p = 0.998).

CONCLUSION

To our knowledge, this is the first study assessing the immune response using neutrophil-to-lymphocyte ratio as a prognostic biomarker in STS treated with pre-operative hypofractionated radiotherapy. In this population, an NLR > 4 was prognostic for recurrence and distant metastasis, but not for overall survival. This study highlights the need for a better understanding of the immuno-biological effects of RT, which should be further addressed in the context of clinical trials due to its simplicity and potential prognostic value.

Toxicity of Patients with Ultra-Central Thoracic Tumors Treated with Stereotactic Body Radiotherapy (SBRT) with Dose of 50 Gy in 5 Fractions

PURPOSE/OBJECTIVE(S)

The ideal regimen for stereotactic body radiotherapy (SBRT) in ultra-central lung tumors is still to be defined, mostly due to the risk of unacceptable or fatal toxicity. There is not much information on outcomes after SBRT for this group of patients. We summarize here our experience with ultra-central lung cancer patients treated with the dose of 50 Gy delivered in 5 fractions.

MATERIALS/METHODS

This study is a retrospective review of all cases of ultra-central thoracic tumors treated with SBRT with the dose of 50 Gy in 5 fractions, delivered every other day, at our institution. In all cases, as we defined ultra-central lung tumor, the PTV overlapped or touched one or more of the following structures: bronchial tree, trachea, great vessels, heart, and esophagus. Metastatic and primary lung lesions were included. The volumes of treatment were defined by 4D-CT to consider breathing motion. Normal organs constraints followed the recommendations of the RTO 0813 trial as follows: Spinal cord: max 30 Gy. Lung right or lung left: V13 Gy[cc] < 1500. Esophagus: max 52 Gy and nonadjacent esophagus: V27.5 Gy[cc] < 5. Heart: V32 Gy[cc] < 15; max 52 Gy. Great vessels: max 52 Gy and non-adjacent great vessels V47 Gy[cc] < 10. Trachea plus bronchus: max 52 Gy and non-adjacent V18 Gy[cc] < 4. Follow-up, at the discretion of the treating MD, included periodic CT scans of the thorax after SBRT and assessment of radiation-induced toxicity scored with CTCv3.0.

RESULTS

Between December 2015 and February 2022, 86 patients were eligible for this review. Median follow-up was 17 months (range: 1-76 months); the median age was 74 years (range: 37-98 years). Histology was as follows: 50 patients had biopsy proved NSCLC, 16 had no biopsy, and 20 had metastatic non-lung primaries. Overlapped structures were as follows: with great vessels in 46 cases, heart in 20 cases, trachea/branchial tree in 18 cases, and esophagus in 2 cases. In 16 patients the overlap was present in more than one structure. Overall, 68.6% did not report acute toxicity. The most common acute side effects were fatigue (15.1%), coughing (8.1%), shortness of breath (6.9%), esophagitis (2.3%), and dysphagia (1.1%). No grade 3 or more significant toxicity was described. As acute side effects, many patients had exacerbations of the previous condition, such as shortness of breath (16 pts) or coughing (4 pts) during follow-up. Pneumonitis was found as a late side effect in four cases. One patient had empyema associated with a fistula in the non-irradiated lung, where the patient had previous surgery, but in the irradiated lung no severe complication was detected. There were no deaths attributed to the SBRT treatment. 67.5% of 86 patients were alive at the time of the review; 87.2% had local control, and 65.1% had metastases-free survival.

CONCLUSION

In this cohort of patients, no death or even severe acute or chronic toxicity was attributed to SBRT. SBRT seems safe for ultra-central lesions using the regimen of 50 Gy in 5 fractions with the constraints of the RTOG 0813 trial.