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Sarcoma surgeons face unique challenges in younger patients with significant skeletal growth remaining. The heightened concerns regarding radiation in the very young and the drastic changes expected in the lengths and cross-sectional areas of bones affect the decision-making for both soft-tissue and bone sarcomas in this population. Nonetheless, there is sparse literature focused on sarcoma surgery in this age group. The records of one tertiary regional sarcoma treatment program were reviewed to identify all patients ten years old or younger at the time of local control surgery for limb or limb-girdle sarcomas. Demographic information, diagnosis, surgery performed, complications, and general outcomes were gleaned from the medical records. 43 patients were identified, including 15 with osteosarcomas, 11 Ewing’s sarcoma family tumors, five rhabdomyosarcomas, and two synovial sarcomas, among others. Location of tumors varied widely, but demonstrated a predilection for the upper extremity more than is typical in adolescents with the same tumor types. Survival was favorable overall, with only five patients dying from disease. Most patients continued to function well at latest follow-up, but 16 experienced additional surgical interventions following the index procedure. Sarcoma surgery in the younger growing child presents challenges for the surgeon, patient, and parents, but is usually successful in the long-term.
Over the last thirty years, surgical options for limb and limb-girdle sarcomas have expanded far beyond the prior, almost exclusive use of proximal amputation. Improved imaging and successful adjuvants such as cytotoxic chemotherapy for most bone sarcomas and radiotherapy for most soft-tissue sarcomas have narrowed the thickness of margins considered necessary to achieve local control of these neoplasms. The surgical practice of limb salvage has become a subspecialty unto itself with the rise of these options and the technologies available to perform them.
Sarcomas generally have a bimodal distribution in the population according to age.1 Most complex genetic soft-tissue sarcomas favor older populations beyond middle age. Bone sarcomas and balanced chromosomal translocation-associated soft-tissue sarcomas, however, have a predilection for adolescents and young adults.
Certainly, the adolescent and young-adult cancer populations proffer plentiful challenges to multidisci plinary sarcoma treatment teams, both surgically and psychosocially. The same sarcomas common in these young populations can also occur – much more rarely – in the very young.2-4 Unique psychosocial, anatomic, mechanical, and biological factors all increase the challenges in sarcoma surgery for the very young child with considerable growth potential remaining. There are few papers in the literature focusing on this population.5-7 We determined to review the experience at our center with surgery in this younger population, hoping to inspire others to do the same.
With the approval of our institutional review board for human subjects research, and following all appropriate legal and ethical guidelines for the same, records were retrospectively reviewed of patients treated at our tertiary referral center for multidisciplinary sarcoma care. Patients 10 years old or younger at the time of surgery were included if they underwent surgery with the intent of wide resection for bone or soft-tissue sarcomas during the first decade of the 21st century. Amputations were not excluded; neither were sarcoma-like wide resection surgeries for borderline, non-malignant diagnoses. Patient medical records and imaging were reviewed. Demographic information, diagnosis, surgery performed, complications, follow-up duration, and general outcome were gleaned from the medical records, and tabulated.
Mean age at index procedure was five years plus six months, ranging from ten days old to ten years (Table 1). The diagnoses included 15 osteosarcomas, 11 Ewing’s sarcoma family tumors, five rhabdomyosarcomas, three pleiomorphic sarcomas, three fibromatosis-related neoplasms, two infantile fibrosarcomas, and two synovial sarcomas, among others. Of these, 17 were located in the upper extremity or shoulder girdle and 26 in the lower extremity or pelvic girdle. All bone sarcomas received neoadjuvant and adjuvant chemotherapy, as did all synovial sarcomas, rhabdomyosarcomas, and Ewing’s sarcoma family tumors in the soft tissues. Three patients received adjuvant radiation; two for narrow margins following resection of Ewing’s sarcoma family tumors and one for a rhabdomyosarcoma in the soft tissues.
Surgeries performed included wide resection alone, or with radiation in 18 patients, resection followed by endoprosthetic reconstruction in nine patients, regional graft reconstructions in four patients, primary amputation in five patients, modified amputations in three patients, distant-site autografting in two patients, and intercalary allograft reconstruction in one patient. Specifically, there were three clavicula pro humero reconstructions8 (Figure 1) and one ulnius,9 or creation of a single-bone forearm (Figure 2).
Among complications, infection and wound healing difficulties were most common, especially in the younger children, with seven affected in total. The sequelae of some of these infections were severe, resulting in rotationplasty in two and tibial turn-up in one. Of note, only one patient under 10 years old, out of four managed initially with long-bone endoprosthetic reconstruction, retains that endoprosthesis at latest follow-up (Figure 3). Most infections were late.
Limb length inequality (LLI) was also common, noted as significant in seven patients. Three patients developed local recurrence; two were managed with re-resection, the other with proximal amputation. One patient had unacceptable margins on initial resection of a tumor that had become complicated by pathologic fracture during neoadjuvant chemotherapy; this recognition was not un-anticipated and prompted proximal amputation under the same anesthetic. Two patients developed fractures from disuse osteopenia shortly after completion of adjuvant chemotherapy.
Nine patients either presented with or developed metastatic disease during their course of treatment and surveillance. Five patients have died from disease and a sixth is alive, but moribund with currently progressing disease.
The ten-and-under population makes up a small portion of the overall volume of sarcoma-related medical care at our institution and also more generally. While many of the same treatment principles and practices are brought to bear on the tumors arising in this younger population, there are unique considerations that our series highlights. For example, a local recurrence rate near five percent remains the goal, but generates a much higher rate of amputation in these young children than in their adolescent counterparts. There were eight primary amputations or modified amputations (Figure 4), and another four performed as secondary procedures. For most of these children, these procedures were chosen from among available options as the most function-preserving operations. Other considerations are also unique to this young population, such as avoidance of radiation, difficulties with skeletal growth, and preference of biologic reconstructions for expected durability.
Radiotherapy is especially undesirable in the very young child due to the increased severity of reactive fibrosis, the growth disturbances expected in radiated bones and other tissues, and a greater concern for secondary cancers arising from irradiated cells that are actively proliferating.10 Although three patients in our series received radiation as part of their initial local control, another ten patients would have likely received adjuvant radiation had they been adults with tumors of similar grade, size, and location. A fourth patient received radiation as part of the management of a local recurrence. In the patients who received radiation, only one specific radiation morbidity, that of equinus contracture following calf radiation, was noted, but at present the follow-up remains short in total duration.
For these patients, doses were minimized – most were guided by Children’s Oncology Group trial protocol specifications – and administered by a pediatric radiation oncology specialist.
Anticipated skeletal growth challenges the decision-making for parents, patients, and surgeons when sarcomas arise in the bones of these young children. Eight patients underwent expandable endoprosthetic reconstructions in our series. Other patient series have focused specifically on such implants.11-13 While the technology for such implants continues to improve, including both non-invasively and minimally-invasively lengthened options, these reconstructions are usually limited to the older patients among this very young population. In patients under ten years old, both the lengthening expected and the smaller diaphyseal cross-sectional areas add additional challenges. Even most successful endoprosthetic reconstructions with expandable implants will require revision to definitive adult implants after skeletal maturity. The cortical atrophy expected around cemented or even press-fit stems in younger children can shorten the usable bone for such secondary reconstructions.14-15 It is with this in mind that, at our center, we often utilize Compress (Biomet) interfaces between the host bone and implant, to both minimize the atrophic changes, and shorten the diaphyseal length utilized that might require subsequent resection on revision reconstruction.16 Nonetheless, no endoprosthetic reconstructive options available on the market today are without inherent pitfalls in the ten-years-old-and-under population. Two of our patients had hardware-related problems requiring revisions prior to skeletal maturity. We noted specifically that only one patient under ten years old in our series of four (in this age range) retained a long-bone endoprosthetic reconstruction at latest follow-up. The difficulty with soft-tissue coverage of unavoidably over-bulky implants in this very young population, as well as the on-going need for subsequent interventions, puts these patients at the highest risk. While rotationplasty remains an excellent secondary salvage operation for many of these patients, it can be much more difficult to perform in the setting of failed endoprosthetic reconstruction, given the stiffening of perivascular and perineural tissues, the compliance of which is critical to successful rotationplasty.
Allografts pose other unique problems for this population wherein significant growth is expected. Although healing of allograft-host junctions may be more readily achieved in younger patients, aggressive cytotoxic chemotherapy likely decimates this healing advantage. There are growth-related issues as well. When allografts must cross or replace physes, longitudinal growth and angular deformities are the expectation in these very young patients, as exemplified by one in our series (Figure 5). These may be managed with guided growth of remaining physes, but such anticipated subsequent interventions must be reviewed with patients and their parents at the initial decision-making discussions. Even when diaphyseal resections can spare physes to permit continued longitudinal growth (rare by the anatomic extent of most tumors), the cross sectional area of the allografts that will fit very young bones will not usually be suitable for the adult bodies that these bones will ultimately support. This creates the necessity for additional surgeries during skeletal growth in most cases.
Such challenges with endoprosthetic or allograft reconstructions in these younger patients led many of the surgical discussions toward more creative biological reconstructive options. Three patients with proximal humerus sarcomas in our series were reconstructed by disarticulating the sternoclavicular joint and swinging the clavicle down, suspended from the acromioclavicular joint to serve as the proximal humerus, termed the clavicula pro humero reconstruction.8,17 As essentially all proximal humerus reconstructive options following wide resection create some form of a hanging arm,18 these clavicula pro humero reconstructions are especially attractive, given the chance for bidirectional active bone healing and a native joint for suspension. Nonetheless, even healthy bone from both the medial clavicle and the distal humerus can be thwarted from healing to each other in the setting of adjuvant chemotherapy, as exemplified by one of our patients. Further, the clavicle is limited in the length it can provide for reconstruction, prompting the use of a fibular autograft between the down-rotated clavicle and the residual humerus in another patient in this series with long involvement of the humerus.
We encourage appropriate patients to strongly con-sider rotationplasty in its varied forms when segmental skeletal resections are required in the lower extremity in the very young.19-21 There were two primary and two secondary rotationplasties in our series as well as one primary tibial turn-up and one secondary tibial turn-up (Figure 6). Although rotationplasty remains less popular in the United States than in Europe or Canada, it has many advantages over some other resection/reconstructive options. The prosthetics that these patients utilize permit essentially unlimited activities. Further, rotationplasty eschews the neurological complications and cut bone-end overgrowth problems of proximal amputation in the very young. In cases where concern for popliteal soft-tissue extension might otherwise make margins unacceptably close following popliteal dissection, the vascular resection and reanastomosis possible in rotationplasty can leave a popliteal vessel segment as an additional layer of marginal tissue. The primary challenges to rotationplasty remain the peer-perception issues that can be expected during adolescence and the lifetime need for specialized prosthetic fittings. This latter concern remains a major impediment for some patients pursuing rotationplasty in the United States as opposed to in nations where medical costs are covered by socialized systems.
The ten-years-old-and-under population represents a portion of sarcoma surgery to which William Enneking’s adage, “There are no rules in tumor surgery,” is aptly applied. Nonetheless, we hope that this publication of our experience, with its inherent challenges, will prompt others to put theirs on more open display as well. There is clearly more art than science advising these surgeries, but just like the best guesses, we hope that art can become better educated. It will be educated by the exchange of ideas and experiences in the literature by those willing to face these challenging cases openly.
Although no funding was received specifically for this project, the authors gratefully acknowledge the general support of National Cancer Institute (NIH) K08CA138764 and Huntsman Cancer Institute Nuclear Control Program funding to Kevin B. Jones, and funding from the Huntsman Cancer Foundation and the Department of Orthopaedics at the University of Utah to both Kevin B. Jones and R. Lor Randall. The authors wish to disclose that R. Lor Randall has previously lectured on behalf of Biomet, but has never had and does not intend to have any ongoing consultancy or intellectual property contracts with the company. Neither the authors nor their family members have any other related, competing financial interests to disclose.