In this report, we describe a 40-year old, female patient with four concurrent primary malignant tumours. The simultaneous occurrence of four malignancies is uncommon, and metastases should be excluded. Indeed, all four tumours exhibited morphological features consistent with their histogenesis. Both breast cancers were hormone receptor positive and included intraductal components as precursor lesions for invasive carcinomas. A recent study by Melhem-Bertrandt
et al., described an ER positive/HER2 positive phenotype for breast cancer in
TP53 germline mutation carriers [
18]. This study also observed that in cases of bilaterality, both tumours were HER2 positive. In our patient, examination of the entire myxofibrosarcoma did not reveal any lipogenic morphology, and similarly, the liposarcoma did not exhibit a myxoid or non-lipogenic component. Furthermore, the liposarcoma expressed the S100 protein, which is an established marker for lipogenic differentiation. The typical combination of sarcomas and early-onset breast cancer was indicative of LFS and subsequent genetic analysis confirmed a germline mutation in the
TP53 gene. While the patient met some of the wider Li-Fraumeni-like-criteria, she did not meet the classical LFS criteria [
4]. The age at onset for the first malignancy was relatively high, as the estimated penetrance at 40

years of age ranges between 77%–100% [
5]. The average age for diagnosis of first cancers in
TP53 mutation carriers is estimated to be 21.9

years, and this is earlier in females than in males [
1,
5]. Predictive testing of minors is recommended since a high prevalence of adrenal gland, soft tissue and brain tumours has been observed in children
Testing of both parents indicated a
de novo TP53 mutation in the patient.
De novo TP53 mutations have been described in up to 23.5% (4 of 17) of carriers [
9,
19]. Recently,
de novo TP53 mutations were confirmed in 7% and suspected in up to 20% of a larger cohort with 75 germline mutation carriers [
20].
Treatment response to adjuvant therapy and prognosis
Impaired response to chemotherapy and radiation is described in most studies [
21-
24]. In breast cancer,
TP53 status was identified as independent negative prognostic marker [
25], however the results remain controversial. The response to treatment ranges from a high rate of pathologic complete remission of breast cancer after neoadjuvant chemotherapy with anthracyclines, to primary tumour resistance and progression as observed in the case of our patient [
26-
31]. Introduction of wild-type
TP53 by gene therapy increased the response to chemotherapy or radiation therapy in preclinical and some early clinical trials [
27,
32-
34], however the results were not consistent and to date, gene therapy is not within reach for patients with LFS.
Treatment-induced secondary cancers
The risk of developing secondary, radiation-induced malignancies was described as elevated in LFS patients, since the first reports of LFS by Li and Fraumeni [
3]. Several case-reports point to the appearance of metachronous cancers in radiation-treated areas in cancer patients with
TP53 mutations [
35-
39].
Data regarding secondary cancers after radiation therapy in young LFS patients is limited, because of the unfavourable prognosis of most core cancers in LFS and the expected time delay in radiation-induced cancers [
19]. Interestingly, five long-term in-field relapses or second primary cancers were recently reported in six patients with unilateral breast cancer, following radiation treatment [
39]. In a study of 27 LFS patients, nine were treated with radiotherapy. Of these, six patients suffered from one or two successive solid tumours in the radiation field within a period of 3–22

years (median 7

years) after treatment for the first malignancy. One additional cancer was identified in the radiation field of a patient following treatment for a third cancer, after a delay of 7

years [
17]. In a separate study, three radiotherapy-treated patients in a series of nine children with adrenocortical tumours and known
TP53 mutations, survived more than two years, however these children developed five secondary malignancies in the radiation fields [
19]. Preclinical studies support the hypothesis that cells lacking wild-type TP53 function have an increased likelihood of genetic instability due to high rates of inappropriate recombination after radiation-induced DNA damage (reviewed in Cuddihy
et al.,[
40]). In
Trp53-heterozygous or
Trp53-null mice, treatment with low-dose irradiation led to shorter latency of tumour development and a higher incidence of malformations [
41-
43]. Human
TP53-deficient cells have been shown to accumulate DNA damage and are susceptible to malignant transformation, whereas
TP53-competent cells showed cell-cycle arrest facilitating DNA repair, or apoptosis [
44]. These data support the observation that LFS patients are more likely to develop radiotherapy-induced secondary cancers. Finally, it appears that in addition to
TP53 variations, the presence of additional genetic alterations are required to predict the individual risk for radiation-induced secondary cancers [
45,
46].
Need for therapy modification in LFS patients
Due to the potentially higher cancer induction rate after radiotherapy, it is important to consider the existence of a germline
TP53-mutation, especially if there is a choice between surgery and radiotherapy [
47,
48]. After bilateral, breast-conserving resection, the initial plan to apply adjuvant radiation therapy was cancelled due to the detection of a germline
TP53 mutation. Greater effort should be taken in the early detection and complete resection of
TP53-associated malignancies, since DNA-damaging, standard adjuvant therapies not only have a questionable effect, but also carry the risk for secondary tumours.
Surveillance
Most of the core cancers of LFS are associated with a poor prognosis. Interestingly, the first prospective data on the successful application of a surveillance programme in
TP53 mutation carriers was recently published. The key imaging procedure was an annual rapid total body MRI starting in childhood. Compared to the control group, this study demonstrated a potential survival benefit using a comprehensive screening program [
49].
Genetic counselling and predictive testing should be offered to patients fulfilling the classic LFS or Li-Fraumeni-like criteria, as well as to their relatives, in order to recommend an intensified cancer screening if LFS is confirmed. While the NCCN guidelines recommend the testing of singular cases suggestive for LFS, even in the absence of family history, others negate the necessity for testing because of low mutation rates (0–7%) and high psychological burden. Numerous publications have explored the testing of early onset breast cancer cases for
TP53 germline mutations and found that these represent rare cases [
1,
11,
50-
57]. For example, no pathologic mutations were found in 95 patients with breast cancer (< 30

years old), despite the fact that several patients displayed a positive family history for breast and ovarian cancer [
50]. As the costs of testing decrease in the future and effective prevention strategies may be confirmed, testing patients with early onset breast cancer without a family history of cancer will become even more feasible.
In comparison to other tumour syndromes, such as hereditary breast and ovarian cancer, prophylactic operations do not offer a good prognosis for carriers of a TP53 germline mutation, and each case should be considered individually. Firstly, the life-time breast cancer risk is estimated to be ~22%. This is significantly lower than for carriers of a pathogenic mutation in BRCA1 or BRCA2, who display a life-time risk for breast cancer of ~60–80%. Secondly, in LFS, malignancies emerge in different anatomical sites, whereas BRCA-associated tumours mainly affect the breast and ovaries.
Since some LFS patients seem to carry an elevated risk for radiation-induced malignancies, exposure should be as low as possible, although a general contraindication for any type of radiological diagnostic or treatment cannot be stated. Surveillance strategies should be chosen with regard to the least possible radiation exposure.