Soft Tissue Sarcoma: The True Zebra You Don’t Want to Miss

By Nathan W. Mesko, MD, Michael J. Joyce, MD, and Steven A. Lietman, MD

ze·bra

noun \ze-br , Canada & British also ze-\

1. Any of several fleet African mammals (Equus burchelli, grevyi, and E. zebra) related to the horse but distinctively and conspicuously patterned in stripes of black or dark brown and white or buff
2. The American medical slang term for arriving at an exotic medical diagnosis when a more commonplace explanation is more likely

An uphill battle

Sarcoma represents a rare form of malignancy, accounting for 1 percent of all adult malignancy diagnoses. Despite long-standing educational efforts to increase recognition and improve practice patterns surrounding sarcoma care, the literature shows persistently high rates (19 to 60 percent) of unrecognized soft tissue sarcomas that undergo inappropriate, margin-positive surgical excision. This troubling trend endures in spite of clear guidelines that help highlight those new “lumps and bumps” that should be considered high risk for a potential sarcoma diagnosis.1,2 Efforts to curb this trend continue, with the goal of early referral of patients with suspicious soft tissue masses to an orthopaedic oncologist to enhance the opportunity for a successful outcome.

How rare is it?

Literature suggests that the average primary care physician or non-sarcoma-trained surgeon encounters a true sarcoma diagnosis only once or twice in his or her career. The American Cancer Society projected that about 12,000 new soft tissue sarcoma diagnoses would be made in 2014.3 This represents only 5 percent of the projected new diagnoses of cancers of the breast, prostate or lung, which helps explain why only a handful of U.S. medical centers have the resources needed to treat and follow patients with a new sarcoma diagnosis effectively. Moreover, it is well established that definitive care administered at high-volume institutions with a functioning multidisciplinary sarcoma team leads to lower complication and mortality rates and better functional outcomes.4

So what’s the big deal?

Unrecognized soft tissue sarcomas can be problematic for two main reasons:

• First, serial observation of a soft tissue mass that is erroneously thought to represent a benign diagnosis (e.g., lipoma, hemangioma or cyst) can lead to a delay in definitive diagnosis. This delay can allow for continued tumor growth, resulting in a larger tumor size at the time of presentation to the treating multidisciplinary sarcoma team ‒ a factor that has been linked to a more negative overall prognosis.
• Second, patients who undergo improper excision of a soft tissue sarcoma (under the false impression that it is a benign soft tissue lesion) face multiple challenges in their future care. In many cases, a second surgery to re-excise the surgical bed is needed, often requiring advanced reconstruction techniques, such as skin grafting, muscle flap coverage, vascular reconstruction or even amputation. Even in simpler scenarios, an improperly placed biopsy tract can lead to a much larger incision (Figure), which carries inherently higher risk for early wound complication. These wound issues may be magnified if radiation is administered to the surgical field in the perioperative period. Beyond concerns about future functionality, incomplete excisions have been linked to increased hospitalization and aftercare expenditures1 and to higher local recurrence rates ‒ even after re-excision and radiation to the surgical field.

Figure. Photos from a case illustrating the consequences of incomplete excision. Left panel: A middle-aged man presented to clinic following excision of a “benign lipoma” at an outside institution. The excision was done through a 10-cm transverse incision over the posterolateral aspect of the left thigh, with a drain placed 3 cm distal to the incision. No preoperative imaging was obtained. Pathology was consistent with a high-grade soft tissue sarcoma. Right panel: In the OR, the incision was marked out to provide no less than 2 cm of skin surrounding the incision, as carefully correlated with a preoperative MRI. The wound ultimately required split-thickness skin graft coverage to achieve closure.

Stakes extend beyond patient outcomes

For physicians, maintaining proper suspicion for such a rare entity can be difficult. In collaboration with Vanderbilt University’s sarcoma team, Dr. Mesko looked at inciting causes for litigation surrounding sarcoma care since 1980,5 with the goal of better describing risk factors for litigation to help improve education. Key findings (Table) included:

• Primary care physicians (34 percent) and orthopaedic surgeons (23 percent) were the most commonly named defendants in sarcoma-related litigation.
• Delay in diagnosis (81 percent) was the most common reason for litigation.
• Nearly two-thirds of verdicts were in favor of the plaintiff in cases involving the most commonly named specialties.
• The average indemnity payment ($2,302,483) approached 10 times the level of previously described mean payments in the surgical specialty and primary care literature.
• Analysis by state revealed no protective effect against sarcoma-incited plaintiff resolution in states that had enacted tort reform vs. those that had not.

The overall study revealed that while sarcomas are rare, the ramifications of incorrectly identifying and treating a potential sarcoma can be very real to both physician and patient.

A sarcoma team that is ready to help

Cleveland Clinic houses a multidisciplinary sarcoma team that comprises multiple physician specialties and has a singular purpose of providing the care and resources to bring about the best possible patient outcome. In addition to our staff of orthopaedic oncologists, this team includes radiation oncologists with special interests in pre-, intra- and postoperative radiation therapy; pathology specialists with expertise in soft tissue sarcoma who minimize chances of a misdiagnosis; and medical oncologists who have deep experience in evaluating the role of adjuvant medical therapy for these rare malignancies. We believe firmly in collaboration with other institutions with specialized sarcoma expertise to answer questions that will push the envelope for sarcoma treatments in the future.

Because sarcoma is a rare entity, any lesion that arouses suspicion for a potential sarcoma diagnosis should have a low threshold for referral to a facility with an orthopaedic oncologist who works as part of a multidisciplinary sarcoma team. Together, with proper sarcoma awareness, we can begin to change these troubling patterns of delayed diagnosis and improper excision surrounding this rare “zebra” diagnosis.

References

1. Alamanda VK, Delisca GO, Mathis SL, et al. The financial burden of reexcising incompletely excised soft tissue sarcomas: a cost analysis. Ann Surg Oncol. 2013;20(9):2808-2814.
2. Venkatesan M, Richards CJ, McCulloch TA, et al. Inadvertent surgical resection of soft tissue sarcomas. Eur J Surg Oncol. 2012;38(4):346-351.
3. Soft tissue sarcoma treatment statistics. American Cancer Society. Available at: http://www.cancer.org/cancer/sarcomaadultsofttissuecancer/detailedguide/sarcoma-adult-soft tissue- cancer-key-statistics. Accessed Oct. 27, 2014.
4. Ogura K, Yasunaga H, Horiguchi H, et al. Impact of hospital volume on postoperative complications and in-hospital mortality after musculoskeletal tumor surgery. J Bone Joint Surg. 2013;95(18):1684-1691.
5. Mesko NW, Mesko JL, Gaffney LG, et al. Medical malpractice and sarcoma care – a thirty-three year review of case resolutions, inciting factors, and at-risk physician specialties surrounding a rare diagnosis. J Surg Oncol. 2014 Aug 22 [Epub ahead of print].

Dr. Mesko is an orthopaedic oncologist with Cleveland Clinic’s Musculoskeletal Tumor Center in the Department of Orthopaedic Surgery.