Changes in neoplastic cell features and sensitivity to mitotane during mitotane-induced remission in a patient with recurrent, metastatic adrenocortical carcinoma

M Seki, K Nomura, D Hirohara, M Kanazawa1, T Sawada1, K Takasaki2 and H Demura

Department of Medicine, Institute of Clinical Endocrinology, School of Medicine, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan

1Department of Pathology, Tokyo Women’s Medical University, Tokyo 162-8666, Japan

2Department of Surgery, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo 162-8666, Japan

(Requests for offprints should be addressed to K Nomura; Email: nomura7@parkcity.ne.jp)

Abstract

A 58-year-old man had adrenocortical carcinoma in the right adrenal gland. The tumour secreted excessive cortisol and dehydroepiandrosterone-sulphate (DHEA-S), and had invaded the right hepatic lobe and vena cava. Eleven months after surgical tumour resection, the serum DHEA-S levels again increased. Local tumour recurrence and a metastasis was found in the lung. Eleven months after surgery chemotherapy with mitotane (o,p’-DDD) was initiated. Twelve weeks of mitotane reduced serum DHEA-S levels and caused these tumours to disappear. The patient was then treated with low- dose mitotane (1.5-2.0 g/day) for 2 years. Serum levels of mitotane remained at less than 10 µg/ml. Although such low serum levels of mitotane and delayed initiation of mitotane after surgery have been proposed to weaken the antineoplastic effect of mitotane, the patient had a remission for 2 years. However, there was then local re-recurrence with an increase in serum DHEA-S and death 4 months later. The histological features of neoplastic cells were quite different comparing tumour resected at surgery and tumour at autopsy. The latter had more frequent mitotic nuclei. This tumour was initially sensitive to mitotane, but later became insensitive.

Endocrine-Related Cancer (1999) 6 529-533

Introduction

Adrenocortical carcinoma is a rare disease whose inci- dence has been reported to be approximately two persons per million a year (Hutter & Kayhoe 1966a). Surgery to remove all the tumour is the only reliable therapy (Venkatesh et al. 1989, Pomier & Brennan 1992, Søreide et al. 1992). Most patients, however, were found to have metastases of stage 3 or 4 which limited the surgical therapy (Cohn et al. 1986, Wooten & King 1993). Mitotane (o,p’-DDD) is the drug of choice for patients with inoperable, recurrent, and/or metastatic tumour. Although significant improvements were reported initially

with mitotane (Hutter & Kayhoe 1966b, Lubitz et al. 1973, Jarabak & Rice 1981, Schteingart et al. 1982, Dickstein et al. 1998), later studies have suggested that mitotane was less effective (Boide et al. 1989, Luton et al. 1990, Vassilopoulou-Sellin et al. 1993). Serum drug levels were found to exceed 14 ug/ml in patients with successful tumour regression (Boven et al. 1984, Van Slooten et al. 1984, Haak et al. 1990, 1994). Longer survival was documented for patients medicated immedi- ately after aggressive surgical therapy (Kasperlik-Zaluska et al. 1995). We present a patient with recurrent, metas- tatic adrenocortical carcinoma who had been treated with a low dose of mitotane for 2 years.

Table 1 Basal hormonal data before and after surgery
Before (February 1995)After (April 1995)Normal range
ACTH (pmol/l)<0.70.82.20-13.2
Cortisol at 0800 h (nmol/l)786.333.1124.2-689.8
at 2200 h783.6ND
after 8 mg Dex560.1ND
DHEA (nmol/l)70.4ND1.70-30.5
DHEA-S (umol/l)95.00.650.35-14.1
Aldosterone (pmol/l)263.5346.861.0-416.1
DOC (pmol/l)1081.9ND221.9-776.7
PRA (ng/(I·s))1.530.860.14-0.83
Urinary free cortisol (nmol/day)1718.9ND<275.9
Urinary 17-OHCS (mg/day)49.41.62.9-11.6
Urinary 17-KS (mg/day)2172.64.6-16.4

ND, not determined; DOC, 11-deoxycorticosterone; PRA, plasma renin activity; Dex, dexamethasone.

Case report

A 58-year-old man was incidentally found in a computerized tomography (CT) examination to have a right adrenal tumour (12×9.5x13 cm) invading the right hepatic lobe and inferior vena cava (Fig. 1A). Although he did not appear Cushingoid, he had high cortisol levels with suppressed adrenocorticotrophin (ACTH), and high dehydroepiandrosterone (DHEA) and DHEA-sulphate (DHEA-S) levels (Table 1). Urinary 17-ketosteroid (17-KS) excretion was also high when compared with urinary 17-hydroxycorticosteroid (17-OHCS) excretion. Serum oestrogen, which influences the SHBG (sex hormone binding globulin) and CBG (corticosteroid binding globulin), was not measured. There was no evidence of metastases. The tumour was resected, including the right hepatic lobe and part of the vena cava, in March 1995 (Fig. 1B). Histological examination was consistent with adrenocortical carcinoma (Fig. 2A). Plasma DHEA-S returned to the normal range and cortisol was low. The patient received hydrocortisone until August 1995. In February 1996, his DHEA-S level increased again. Computerized tomography examination revealed local tumour recurrence (5.5x5.5x8 cm) (Fig. 3A) and a solitary nodule (2.5x2 cm) in the right lung (Fig. 3C). He was diagnosed with recurrent and metastatic tumour 11 months after surgery. Chemotherapy with mitotane, which was micronized and mixed with cellulose acetylphthalate, was initiated in April 1996, initially at 1.5 g/day and gradually increased to 6 g/day at maximum (Fig. 4). Serum mitotane levels were measured by gas chroma- tography as described in the Materials and methods

section, and found to be changed according to the dosages used (Fig. 4). The serum levels remained below 9.2 mg/ ml. After 12 weeks of mitotane, the metastatic tumour in the lung and the local recurrence disappeared (Fig. 3B and D). Plasma DHEA-S decreased to an undetectable level, and ACTH increased. These findings suggested that mitotane induced tumour regression with inhibition of adrenal steroidogenesis. After that, the patient was treated with low-dose mitotane (1.5-2.0 g/day) and with hydrocortisone (or dexamethasone). No metastases or recurrence were observed until April 1998. Routine laboratory data were normal except for high levels of gamma glutamyl transferase (y-GTP). Although y-GTP appeared to reflect the adverse effect of mitotane, the patient agreed to continue medication unless side-effects become severe. Serum cholesterol has been reported to be increased by mitotane, but remained rather low (3.21-4.45 nmol/l) in this patient. Serum mitotane concentration was measured several times, and was 9.2 ug/ml at maximum (Fig. 4). In April 1998, serum DHEA-S increased abruptly and CT examination revealed local tumour recurrence. Although the dose of mitotane was increased, direct tumour invasion to the retroperitoneum and rapid haematogenous metastases in the right kidney and the remaining liver accelerated during the last 3 months. Tumour thrombus in the inferior vena cava caused severe oedema of the lower limbs and ascites. Finally, in August 1998, rupture of a haematogenous metastases in the liver caused death. Autopsy and pathological examination was permitted. Morphology of the carcinoma cells was different from that in 1995 (Fig. 2B). In particular, mitotic nuclei were more prominent. In the region of the previous

Figure 1 Abdominal CT scans before and after surgical therapy. (A) A large adrenocortical carcinoma with calcification invading the right hepatic lobe and vena cava. The scan was made in February 1995. (B) Post-surgical scan from April 1995. The tumour was completely resected. Partial hepatectomy and a vena cava graft were carried out. The scale bar has a length of 5 cm.

A

B

lung metastases, there were no carcinoma cells, but only focal fibrosis.

Materials and methods

Serum mitotane concentrations were determined based on methods described by Moolenaar et al. (1997) with minor modifications at the Hoechst Marion Roussel laboratory in Japan. Briefly, to 0.5 ml serum, 5 ml diethyl ether and 0.1 ml internal standard solution (80.0 µg/ml nervonic acid methyl ester) were added and the mixture was vortexed, followed by freezing at -20 ℃. A diethyl ether layer was recovered, evaporated, and reconstituted with 0.1 ml chloroform to be injected into the gas chromatograph (Hewlett Packard HP-5890 series II equipped with FID and DB-23 column (J & W Scientific, Folxam, CA, USA)). Plasma for drug monitoring was taken in the morning, 2-3 h after drug administration.

Figure 2 Histological examination of tumours (haematoxylin and eosin × 200). (A) Histology of the resected tumours by surgery in March 1995. Atypical cells with hyperchromatic nuclei, eosinophilic cytoplasm and significant pleomorphism were observed. The cellular construction was disordered. (B) Histology of the tumour at autopsy in August 1998. The tumour was composed of small cells forming trabecular or solid patterns. Large hyperchromatic nuclei, marked cellular pleomorphism and structural disorder were not conspicuous. Mitotic nuclei, indicated by the arrow, were more prominent than in March 1995. The scale bar has a length of 20 mm.

A

B

Discussion

To obtain the best antitumour effect of mitotane, monitoring of the serum level, and immediate medication after aggressive tumour resections (including distant metastases) have been proposed. The effect of mitotane may not be wholly related to tumour steroidogenicity (Hutter & Kayhoe 1966b, Schteingart et al. 1982, Dickstein et al. 1998).

Van Slooten et al. (1984) reported that seven of eight patients with tumour regression had serum mitotane levels exceeding 14 ug/ml, while 19 of 20 patients without tumour regression had serum mitotane levels below 14 µg/ ml. These findings suggested target mitotane serum level above 14 µg/ml. Haak et al. (1994) studied 62 patients

Figure 3 Chest and abdominal CT scans before and after mitotane therapy. (A) Abdominal CT scan in April 1996 at local recurrence. (B) Abdominal CT scan in July 1996, taken 12 weeks after mitotane treatment. The recurrent tumour disappeared. (C) Chest CT scan in July 1996 demonstrating a tumour metastasis in the right lower lung (arrow). (D) The lesion in the lung had disappeared by 12 weeks after mitotane treatment in April 1996. The scale bar has a length of 5 cm. The arrows indicate the tunour.

A

B

C

D

and reported that mitotane treatment resulting in low serum levels (<14 µg/ml) was ineffective. To achieve such serum levels, mitotane was given starting with a dose of 4- 8 g per day, and increased gradually (Van Slooten et al. 1984). Daily doses between 3 and 5 g have been used for

long-term treatment in most patients (Van Slooten et al. 1984, Haak et al. 1994, Kasperlik-Zaluska et al. 1995). Higher doses such as 4-16 g/day have been reported to be unacceptable to most patients because of major side- effects including CNS toxicity (Hutter & Kayhoe 1966b,

Figure 4 Medication and examination time course. Doses of steroids and mitotane, plasma DHEA-S and ACTH, and serum y-GTP and mitotane levels are shown.

Serum mitotane level (ug/ml)

0.6 3.4 5.8

3.5

11.41 9.2

DHEA-S (umol/L)

-GTP (IU/L)

ACTH (pmol/L)

CT

CT

CT

CT

CT

CT CT

40

800

100

30

0

o

600

-GTP

20

400

0

0

0

ACTH

50

10

200

5

DHEA-S

0

0

96 March

August

‘97 January

June

November

‘98 April

Days

Mitotane dose (g/day)

6.0

Death

4.5

3.0

3.0

3.0

1.5

2.0

2.0

1.5

Steroid dose (mg/day)

Dexamethasone 0.3-0.5

Hydrocortisone 5-10

Haak et al. 1994). Compared with these reports, our dosages were relatively low, i.e. an initial and maximum dose of 6 g/day, followed by a maintenance dose of 1.5 g/ day. The serum mitotane level remained below 10 mg/ml throughout treatment. Thus, the mitotane level may not have been the principal factor for tumour regression in our case. A recent report of the combination of carefully repeated removal of all tumorous lesions including metastases together with prophylactic use of low doses of mitotane allowed a long remission period (Dickstein et al. 1998).

Longer survival is anticipated in patients treated early for adrenocortical cancer (Søreide et al. 1992). Adjuvant mitotane chemotherapy lengthened survival when initia- ted immediately after aggressive tumour resection. Ten of 13 patients treated by surgery and immediate long-term adjuvant mitotane administration survived, compared with among 13 given mitotane 3-15 months after surgery (Kasperlik-Zaluska et al. 1995). Others also reported good survival with immediate mitotane therapy after aggressive surgery (Schteingart et al. 1982). Although our patient was treated with mitotane 11 months after aggressive surgery, mitotane treatment was associated with successful tumour regression. Therefore, at that time, the tumour may have been very sensitive to mitotane.

Mitotane induced complete remission in this patient for 2 years. Metastatic tumour in the lung disappeared. Locally recurrent tumour also disappeared initially, but re-recurred after 2 years with a rapid growth rate. Histological examination (Fig. 2B) of re-recurrent tumour after treatment with mitotane showed increased numbers of mitoses and invasion of the tumour capsule. Thus, the tumour became resistant to mitotane.

Our case indicates the importance of tumour sensitiv- ity to mitotane in treating adrenocortical carcinoma. The transformation to a more malignant phenotype, however, limited the antitumour effect of mitotane.

Acknowledgements

We thank Ms June Streimun-Setoguchi for editing the manuscript.

References

Boide B, Novick AC, Pontes JE, Straffon RA, Montie JE, Babiak T, Sheeler L & Schumacher P 1989 The Cleveland Clinic experience with adrenal cortical carcinoma. Journal of Urology 141 257-260.

Boven E, Vermorken JB, Van Slooten H & Pinedo HM 1984 Complete reponse of metastasized adrenal cortical carcinoma with o,p’-DDD. Cancer 53 26-29.

Cohn K, Gottesman L & Brennan M 1986 Adrenocortical carcinoma. Surgery 100 1170-1177.

Dickstein G, Shechner C, Arad E, Best LA & Native O 1998 Is there a role for low doses of mitotane (o,p’-DDD) as adjuvant therapy in adrenocortical carcinoma? Journal of Clinical Endocrinology and Metabolism 83 3100-3103.

Haak HR, van Seters AP & Moolenaar AJ 1990 Mitotane therapy of adrenocortical carcinoma (Letter). New England Journal of Medicine 323 758.

Haak HR, Hermans J, van de Velde CJH, Lentjes EGWM, Goslings BM, Fleuren GJ & Krans HMJ 1994 Optimal treatment of adrenocortical carcinoma with mitotane: results in a consecutive series of 96 patients. British Journal of Cancer 69 947-951.

Hutter AM & Kayhoe DE 1966a Adrenal cortical carcinoma. Clinical features of 138 patients. American Journal of Medicine 41 572-580.

Hutter AM & Kayhoe DE 1966b Adrenal cortical carcinoma: results of treatment with o,p’-DDD in 138 patients. American Journal of Medicine 41 581-592.

Jarabak J & Rice K 1981 Metastatic adrenal cortical carcinoma: prolonged regression with mitotane therapy. Journal of the American Medical Association 246 1706-1707.

Kasperlik-Zaluska AA, Migdalska BM, Zgliczynski S & Makowska AM 1995 Adrenocortical carcinoma: a clinical study and treatment results of 52 patients. Cancer 75 2587-2591.

Lubitz JA, Freeman L & Okun R 1973 Mitotane use in inoperable adrenal cortical carcinoma. Journal of the American Medical Association 223 1109-1112.

Luton JP, Cerdas S, Billaud L, Thomas G, Guilhaume B, Bertagna X, Laudat MH, Louvel A, Chapuis Y, Blondeau P, Bonnin A & Bricaire H 1990 Clinical features of adreno- cortical carcinoma, prognostic factors, and the effect of mitotane therapy. New England Journal of Medicine 322 1195-1201.

Moolenaar AJ, Niewint JWM & Oei IT 1977 Estimation of o,p’-DDD in plasma by gas-liquid chromatography. Clinica et Chimica Acta 76 213-218.

Pomier RF & Brennan MF 1992 An eleven-year experience with adrenocortical carcinoma. Surgery 112 963-971.

Schteingart DE, Motazedi A, Noonan RA & Thompson NW 1982 Treatment of adrenal carcinomas. Archives of Surgery 117 1142-1146.

Søreide JA, Brabrand K & Thoresen SØ 1992 Adrenal cortical carcinoma in Norway 1970-1984. World Journal of Surgery 16 663-667.

Van Slooten H, Moolenaar AJ, Van Seters AP & Smeenk D 1984 The treatment of adrenocortical carcinoma with o,p’-DDD: prognostic implications of serum level monitoring. European Journal of Cancer 20 47-53.

Vassilopoulou-Sellin R, Guinee VF, Klein MJ, Taylor SH, Hess KR, Shultz PN & Samaan NA 1993 Impact of adjuvant mitotane on the clinical course of patients with adrenocortical cancer. Cancer 71 3119-3123.

Venkatesh S, Hickey RC, Sellin RV, Fernandez JF & Samaan NA 1989 Adrenal cortical carcinoma. Cancer 64 765-769.

Wooten MD & King DK 1993 Adrenal cortical carcinoma. Cancer 72 3145-3155.