title: Outcome of patients with soft tissue tumours of the abdominal and pelvis
Creators: name: Su Sivarajah, Sharmini
Publisher: name: University of Glasgow
Year: 2017
Subjects: subject: Retroperitoneal sarcomas, outcomes, prognostic factors, long-term survival, MGPS, laparoscopic.

description: Chapter 1: Long-term outcomes and the pattern of recurrence in patients with a retroperitoneal sarcoma: a 25-year study.

Retroperitoneal sarcomas (RPS) are rare tumours with an annual incidence of 2.7 cases per million. Long-term survival for patients with RPS is poor because of the high frequency of local recurrence, as well as, the difficulty in obtaining adequate margins due to anatomical constraints and the sheer size of tumour. However, there is little-detailed information on the pattern of this recurrence. One wonders if the local recurrences do indeed recur at the site of primary resection or whether it is diffuse intra-abdominal disease. Another area of debate is the role of adjuvant therapy in particularly, radiotherapy in prolonging long-term survival and local control in these patients. Unfortunately, results to date have been controversial.
Thus, the aims of this study are first to examine the long-term outcome of all patients presenting to one unit, to assess the pattern of intra-abdominal recurrence following macroscopic clearance of a primary RPS and to determine the outcome of these patients as well as those who develop distant metastases. Lastly, we would also evaluate whether radiotherapy influences overall survival and local recurrence-free survival in patients with a RPS.

Results:
During the study period, 137 consecutive patients were identified of which 125 had an attempted resection of sarcoma. 112 (89.6%) had macroscopic clearance of tumour while 13 (10.4%) had a debulking operation only. A total of 180 operations were undertaken in the group over the study period.

The 5 and 10-year overall survival rates for all patients including those who did not have an operation or were debulked were 49.7% and 30.7% respectively. The 5 and 10-year overall survival rates for those who had macroscopic resection of their tumour were 62.8% and 42.1% respectively. On multivariate analysis, tumour grade (p = 0.048), type of surgical resection (p &lt; 0.001) and histologic subtype (p = 0.024) were independent predictors of overall survival. For local recurrence-free survival and metastatic-free survival, both tumour grade and microscopic clearance were predictors of outcome.

At a median follow-up of 6.3 years (i.q.r. 2.8-10.6 years), 69 patients have developed recurrent disease. 46 (66.7%) recurred intra-abdominal while 13 (18.8%) had distant metastases. 10 (14.5%) had both intra-abdominal recurrence and distant metastasis. Of the 46 intra-abdominal recurrences, 25 recurred at the resection site of the primary RPS while 5 had a solitary recurrence away from the resection site. 16 patients had either diffuse intra-abdominal (12) or retroperitoneal (4) sarcomatosis and had either palliative debulking or chemotherapy. The median survival for patients who developed 'true' local
recurrence as their first recurrence was 15 months compared to 13 months for those who had distant metastases, P = 0.718.

33 patients received radiotherapy, and 72 patients did not. There were significantly more patients who had microscopic clearance (p = 0.0001) as well as a higher frequency of liposarcomas (P = 0.0191) in the non-radiotherapy group. Among those who received radiotherapy, the 5 and 10-year overall survival rates were 50.7% and 32.5% respectively. The median survival was 64 months (i.q.r. 38 - 90 months). The 5 and 10-year survival rates for those who did not receive radiotherapy were 67.2% and 47.2% respectively. The median survival was 117 months (i.q.r. 97 - 135 months). There was no significant difference in overall survival comparing patients who received radiotherapy with those without, p = 0.121; HR 1.54 (95% CI 0.90 – 2.65). There was also no significant difference in local recurrence-free survival between the two groups of patients, p = 0.056; HR 1.87 (95% CI 0.99 – 3.66).

Conclusion:
This study indicates a relatively high frequency of Grade 3 tumours and the long-term outlook for patients with a retroperitoneal sarcoma remains poor. Results suggest that tumour biology plays a significant role in determining survival even when macroscopic clearance is achieved.

Our data also indicate that more than 50% of all patients who recurred develop distant metastases or diffuse intra-abdominal disease sometime during their follow-up. 'True' local recurrence occurred in 36% of cases only. It comes to no surprise that radiotherapy has no influence on overall survival in patients with a RPS as patients tend to develop multifocal disease of which systemic therapy will have a role in prolonging survival. Most likely targeted therapy, systemic chemotherapy or HIPEC will be the way forward to achieve disease control for these patients as most patients will develop diffuse disease or distant metastasis.

Chapter 2: Modified Glasgow Prognostic Score (mGPS) as an independent prognostic factor in patients with a retroperitoneal sarcoma.

In the last ten years, the theory surrounding the role of systemic inflammation in cancer progression and metastases has attracted some interest. The modified Glasgow prognostic score (mGPS) has been reported to be a significant prognostic factor for a range of tumours. This study examines the significance of the modified GPS for the prognosis of patients with a retroperitoneal sarcoma.

Results:
A total of 100 patients were available for analysis. Macroscopic clearance was achieved in 85% of cases. Tumour grade showed a significant relationship with the mGPS but conversely was not affected by age, histology, gender and type of resection. In the multivariate analysis, tumour grade (p = 0.032), type of resection (p = 0.000) and mGPS (p = 0.039) were identified as independent prognostic factors for overall survival in patients with a retroperitoneal sarcoma. For metastatic-free survival, only tumour grade (p = 0.039) and type of resection (p = 0.014) were predictors of outcome.

Conclusion:
This study demonstrated that mGPS independently predicts overall survival but not for metastatic-free survival in patients with a retroperitoneal sarcoma. The assessment of mGPS could assists in the identification of patients with poor prognosis and be a hierarchical factor in future retroperitoneal sarcoma clinical trials.

Chapter 3: Role of minimal access surgery in the management of abdominal and retroperitoneal tumours.

The role of laparoscopy in patients presenting with an abdominal soft tissue tumour is limited, and most are reports of single cases. This is a study aimed to describe the authors' experience with laparoscopic resection of an abdominal soft tissue tumour of 10 cm or less, particularly in patients who present with a histologically proven soft tissue tumour.

Results:
In this study, 50 patients with a median age 55 years (43 - 64 years) were assessed for laparoscopic resection of 51 abdominal soft tissue masses on CT. 48 patients had attempted laparoscopic resection while two had a biopsy of the tumour only. Macroscopic clearance of tumour was achieved in 42 (87.5%) patients. R0 resection was achievable in 36 patients (75%). The median hospital stay was two days (1 - 3 days), and the median size of the resected soft tissue mass was 62 mm (37 - 90 mm). Six patients were converted to open (12%), and there was no postoperative death. Three patients (6%) developed postoperative complications within 30 days period.

32 of the 50 patients had a histologic confirmation of a soft tissue tumour of whom 17 had a malignant pathology. Complete resection was achieved in 81.3% of all tumours while R0 resection for malignant tumours was achievable in 70.6%. The median tumour size resected was 75 mm (44 - 95 mm). One patient developed a recurrent tumour with a median follow-up of 33 months (i.q.r 17- 37 months).

11 patients had a laparoscopic resection of a retroperitoneal sarcoma. Overall survival was compared to those who had an open procedure. There was no significant difference in the 2-year overall survival between the two groups. However, the length of hospital stay was significantly longer in the open group (P = 0.053).

Conclusion:
Laparoscopic resection of an abdominal soft tissue tumour, particularly a soft tissue sarcoma of 10 cm or less is feasible with macroscopic resection rates similar to that observed for open surgery.